WILD (visual stream)

Uživatelský avatar
ATA
Příspěvky: 1602
Registrován: stř, 28. kvě 2008, 18:55
Bydliště: Litovel
Kontaktovat uživatele:

WILD (visual stream)

Příspěvekod ATA » úte, 19. srp 2014, 20:04

LIMITS
Fovea angle/size of object
Obrázek

SIZE

Vertical
Obrázek
Horizontal
Obrázek
Pink: line of sight
Green: normal vision physical limitation by tissue arount the eyes , nose
Blue: non-restricted vision field (form a circle)
Red: limit of visul surface given my max eye movement (yellow binocular)

max eye positions :
up
Obrázek
down
Obrázek
Obrázek
Obrázek
Eye visual fieled size by retinotopic mapping:
Obrázek
Obrázek
Obrázek
Obrázek
Help! I'm a multidimensional being trapped in a linear time-space continuum!

Uživatelský avatar
ATA
Příspěvky: 1602
Registrován: stř, 28. kvě 2008, 18:55
Bydliště: Litovel
Kontaktovat uživatele:

Global Workspace Dynamics: Cortical “Binding and Propagation

Příspěvekod ATA » ned, 07. zář 2014, 11:54

Global Workspace Dynamics: Cortical “Binding and Propagation” Enables Conscious Contents
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3664777/

notes:
*global workspace (GW) is a functional hub of binding and propagation in a population of loosely coupled signaling elements
*The resulting conscious gestalt may ignite an any-to-many broadcast, lasting ∼100–200 ms, and trigger widespread adaptation in previously established networks
*coalitions that can broadcast via theta/gamma or alpha/gamma phase coupling
*Spatiotopic activity maps can bind into coherent gestalts using adaptive resonance (reentry). Single neurons can join a dominant coalition by phase tuning to regional oscillations in the 4–12 Hz range.
*Foveal patches can be roughly considered to be 1000 × 1000 arrays of light receptors that are echoed point-to-point in retinal ganglion cells, whose axons make up the optic nerve. Ganglion cells are mirrored in the visual thalamus (LGN), which transmit signals point-to-point to V1
*A variety of high-level wave-like phenomena emerge in the C-T system, including standing and traveling waves, spiral vortices, centrifugal propagation, phase coupling and decoupling, microstates, cross-frequency coupling, and hemisphere-wide phase transitions at theta-alpha rates (Freeman et al., 2003; Izhikevich and Edelman, 2008). Complex waveforms in the core range from 0.1 to 200 Hz, with momentary spikes up to 600 Hz.
*“frame binding,” which is equally necessary, where “frames” are defined as visual arrays that do not give rise to conscious experiences, but which are needed to specify spatial knowledge within which visual objects and events become conscious. Powerful illusions like the Necker Cube, the Ames trapezoidal room, the railroad (Ponzo) illusion are shaped by unconscious Euclidian assumptions about the layout of rooms, boxes, houses, and roads.
* In vision the dorsal “framing” stream and “feature-based” ventral stream may combine in the medial temporal cortex (MTL)
*On the motor side there is extensive evidence for trainable voluntary control over single motor units and more recently, for voluntary control of single cortical neurons (Cerf et al., 2010).
*Dynamic Global Workspace theory suggests that FOKs are bound and propagated from non-sensory regions of cortex, such as the classical association areas, frontoparietal regions, and the anterior temporal cortex. Brain imaging suggests that semantic knowledge is distributed in temporal, frontal, and parietal cortex, while sensory regions are recruited for imagery, inner speech, and motor activities that are associated with abstract concepts. However, effortful FOKs appear to be relatively localized in DL-PfC and ACC regions. Effort-related BOLD activity spreads outward as tasks grow more difficult (Tables ​
Help! I'm a multidimensional being trapped in a linear time-space continuum!

Uživatelský avatar
ATA
Příspěvky: 1602
Registrován: stř, 28. kvě 2008, 18:55
Bydliště: Litovel
Kontaktovat uživatele:

Re: WILD (visual stream)

Příspěvekod ATA » ned, 07. zář 2014, 13:08

Cross-frequency phase synchronization: A brain mechanism of memory matching and attention
http://bernardbaars.pbworks.com/f/cross ... &+attn.pdf

*Increased power of fast rhythmic responses at gamma frequency (beyond 30 Hz) can be observed during processing of attended vs. unattended stimuli independent of sensory modality

*shift of spatial attention modulates phase synchronization between theta and gamma activity in the parieto
-occipital cortex. When an internal representation of an expected stimulus meets amatching sensory input, theta activity (reflecting top-down processes) and gamma oscillations (representing bottom-up processes;

*Thereby in contrast to gamma, theta frequency undergoes a phase resetting enabling gamma and theta frequency to synchronize when a target is attended.
Help! I'm a multidimensional being trapped in a linear time-space continuum!

Uživatelský avatar
ATA
Příspěvky: 1602
Registrován: stř, 28. kvě 2008, 18:55
Bydliště: Litovel
Kontaktovat uživatele:

Re: WILD (visual stream)

Příspěvekod ATA » stř, 17. zář 2014, 15:39

“What” versus ”where” in mental imagery
Analogous to the distinction between the ventral “what” and the dorsal “where”
processing pathways as established in visual perception, a dichotomy seems to exist
between object imagery and spatial imagery. This dichotomy has been thoroughly
investigated using tasks that involve mental processing of object categories or specific
visual features and tasks that require imagining spatially coded information.
During object imagery, category-specific regions in the temporal lobe are
activated (Ishai et al., 2000; O'Craven and Kanwisher, 2000; Ishai et al., 2002). For
instance, Ishai et al. (2000) showed that the mental imagery of faces, houses and chairs
evoked differential activation in three regions in the ventral temporal cortex, similar to
the perception of these categories. O’Craven & Kanwisher (2000) demonstrated category-
specific activation for the imagery of houses and faces in, respectively, the
parahippocampal gyrus and the fusiform gyrus. These same regions were activated
during the perception of places and faces. Compared to perception, the magnitude of
Blood Oxygenation Level Dependent (BOLD) responses was smaller during imagery.
Ishai et al. (2000) also demonstrated that the volume of activation was more restricted
during imagery, compared to perception. Perception and imagery of objects thus
activate similar regions in the temporal cortex, but activity is typically more restricted in
magnitude and/or volume during imagery.
Like-wise, during tasks that involve imagining spatial information, regions in
the dorsal pathway were activated (see a.o. Mellet et al., 1996; Alivisatos and Petrides,
1997; Knauff et al., 2000; Mellet et al., 2000; Formisano et al., 2002; Trojano et al., 2004)
.
Specifically the posterior parietal cortex has shown to play a prominent role in visuo-
spatial imagery. Formisano et al. (2002) showed that comparing the angles of the hands
of two imagined clocks evoked bilateral posterior parietal activity. Applying repetitive
Transcranial Magnetic Stimulation (TMS) to this same region resulted in a decreased
performance on the visual spatial task, hence supporting the important role of the
“where” pathway in performing visual spatial imagery (Sack et al., 2002). These studies
also found a latency difference between the left and right posterior parietal cortex during
spatial imagery, suggesting a separate hemispheric specialization. Confirmed by the
results of another TMS study (Sack et al., 2005) it was suggested that the left parietal
cortex generated mental images, while the right parietal cortex was involved in the
spatial comparison of the mental image.


----
The central executive is proposed to perform a controlling function over the two
slave-systems, the visuospatial sketchpad and the phonological loop, and is involved
during manipulation of information from these subsystems. The subsystems each
provide storage and maintenance for two different memory components: phonological
and visuo-spatial information. The dichotomy between these two subsystems has been
supported by decades of empirical research (Repovs and Baddeley, 2006). Within the
visuo-spatial component another distinction has been made between visual (object) and
spatial information. Visual and spatial mental imagery, especially the maintenance of
this information, seems to rely on these subcomponents of the working memory model.
The newly added component of Baddeley’s working memory model, the episodic buffer,
forms a link between the two subsystems and long-term memory, by integrating
information into a scene or episode (Repovs and Baddeley, 2006).
Obrázek
Obrázek
Help! I'm a multidimensional being trapped in a linear time-space continuum!

Uživatelský avatar
ATA
Příspěvky: 1602
Registrován: stř, 28. kvě 2008, 18:55
Bydliště: Litovel
Kontaktovat uživatele:

Re: WILD (visual stream)

Příspěvekod ATA » stř, 17. zář 2014, 17:00

*Vibrace
*Reinterpretace

Mental images of bistable ambiguous figures (i.e., figures with two more or less equally plausible interpretations) such as the Necker cube and the duck-rabbit (figure 3).

Chambers & Reisberg (1985) first introduced their subjects to the concept of bistable ambiguous figures by showing them some examples, then showed them one of the figures that they had not previously seen, but only for 5 seconds, too short a time for them to see more than one of the possible interpretations. They were then asked to form a mental image of the figure they had just seen, and to try to find a second interpretation in their image. Despite having plenty of time, and being given hints and encouragement by the experimenters, in no trial (out of 55 in all) did any of the subjects manage to see or even guess the alternative interpretation. Even more strikingly, when the subjects were then asked to draw the figures they had seen, on the basis of the image they had formed, in the vast majority of cases they were soon able to see the alternative interpretation in their own drawing.

It should be admitted that in other experiments it has been shown that the reinterpretation or reconstrual of images is possible under some circumstances (Finke et al., 1989; Reisberg & Chambers, 1991; Peterson et al., 1992; Brandimonte & Gerbino, 1993; Cornoldi et al., 1996; Mast & Kosslyn, 2002a; Thompson et al., 2008). Nevertheless, this does nothing to undermine the integrity of the original results, and others that point in the same direction (Reed, 1974; Palmer, 1977; Reisberg et al., 1989; Slezak, 1991, 1992, 1995). People clearly experience significant difficulties in reconstruing their mental images under conditions where they have very little trouble with the equivalent picture. Images differ from pictures because they seem to carry their interpretation within them in a way that pictures (even quasi-pictures) do not.
Help! I'm a multidimensional being trapped in a linear time-space continuum!

Uživatelský avatar
ATA
Příspěvky: 1602
Registrován: stř, 28. kvě 2008, 18:55
Bydliště: Litovel
Kontaktovat uživatele:

Re: WILD (visual stream)

Příspěvekod ATA » stř, 17. zář 2014, 22:47

Obrázek
Figure 4.2: The formal framework of PIT. The mental imagination of a scene starts with 1) the retrieval of a set of mental concepts from C-LTM which conceptually describe the scene; 2) these mental concepts are successively instantiated with perceptual information by the cyclic process of select-execute-identify; 3) an interpretation is drawn from all identified mental concepts with their instances of perceptual information; 4) this interpretation constitutes the mental image of the scene.
Obrázek
Obrázek
Help! I'm a multidimensional being trapped in a linear time-space continuum!

Uživatelský avatar
ATA
Příspěvky: 1602
Registrován: stř, 28. kvě 2008, 18:55
Bydliště: Litovel
Kontaktovat uživatele:

Re: WILD (visual stream)

Příspěvekod ATA » stř, 17. zář 2014, 23:11

Differences Between Stimuli of Mental Reinterpretation

I will first elaborate why stimuli like the duck-rabbit are very hard to mentally reinterpret as a mental image and then apply this explanation to the finding that other types of stimuli are easier to mentally reinterpret.

Stimuli That are Difficult to Mentally Reinterpret
Mental reinterpretation generally poses the question why the same ambiguous stimuli are very easy to reinterpret in visual perception while they are hard to mentally reinterpret using mental images. I will use the duck-rabbit as a representative example for those stimuli whose mental reinterpretation has been shown to be hard. The duck-rabbit (depicted in Figure 6.1) has been used in almost all considered studies on mental reinterpretation and is, furthermore, very similar to other stimuli such as the goose-hawk or the chef-dog (see Section 2.1.2 for an overview of different ambiguous stimuli). The hardness of mental reinterpretation strongly indicates that there must be a critical difference between visual perception and mental imagery with respect to (re-)interpretation. Section 3.2.6 outlined differences between visual perception and mental imagery based on the assumptions of PIT. PIT poses that the key difference with respect to mental reinterpretation is the fact that in visual perception we are able to draw an interpretation basically “from scratch”, i.e., with little bias towards a (previous) interpretation. In mental imagery, in contrast, the process of reinterpreting an imagined stimulus requires a mental image of that stimulus. That is, before a mental image is inspected, it needs to be generated. The representation of a mental image, however, corresponds to an interpretation drawn from the set of all mental concepts and their instantiation of perceptual information (see Section 3.2.6). This interpretation will include the mental concepts of the conceptual description retrieved from conceptual long-term memory. The reason these mental concepts are included in the initial interpretation is simply that they are the conceptual description of what is to be imagined. To put it simply, generating a mental image of the duck-rabbit stimulus that was recognized as a duck, will lead to a mental image with the interpretation “duck” and the respective mental concepts describing the parts of a duck. That is, before the mental image could be potentially reinterpreted as “rabbit”, it is necessarily imagined as “duck”.

In order to find an alternative interpretation, a set of mental concepts has to be identified from the perceptual information so that these mental concepts could form a coherent alternative interpretation. However, in mental imagery, the perceptual information is not taken from the (ambiguous) real-life stimulus but it is generated as instances of those mental concepts which have been retrieved from conceptual long-term memory. Therefore, the perceptual information available “fits” the initial interpretation. Because mental images are based on abstracted mental concepts, the generated perceptual information will not exactly resemble that of the original stimulus but will rather be prototypical for the given mental concepts. This point is supported by an experiment reported in (Chambers & Reisberg, 1992). They briefly showed participants the duck-rabbit so that only one interpretation of it was recognized. Participants then compared their mental image to pictures of slightly modified duck-rabbits. The modifications were made to parts of the duck-rabbit which are only relevant for one of the two interpretations, e.g., removal of the mouth of the rabbit and changes to the beak of the duck. Participants were less likely to notice changes to the original stimulus that are irrelevant to their interpretation and more likely to notice changes relevant to their interpretation. These results support the assumption that a mental image is formed specific to one’s initial interpretation and might even lack some of the details of the original stimulus that would allow a successful mental reinterpretation.

Summarizing, in mental imagery, a mental (re-)interpretation has a strong bias towards the initial interpretation of the mental image. This bias has two reasons. The first reason is the fact that there already is an initial interpretation which would have to be “overwritten” by an alternative interpretation. And the second reason is that the perceptual information from which (alternative) mental concepts can be identified has been generated to specifically fit the mental concepts of the initial representation.

This bias can explain why mental reinterpretation is generally hard. It is worth repeating that mental reinterpretation without any sort of hints and with visually presented stimuli has been shown to be very hard. For example, no participant managed to find the second interpretation of either the duck-rabbit, the Necker cube, or the Schröder staircase (all are depicted in Figure 6.1) in the original experiments of Chambers and Reisberg (1985). Slezak (1995) reports similar results for a variety of different ambiguous stimuli, e.g., requiring rotation, figure/ground reversal, the Kanizsa Illusion2 2These stimuli require the combination of the contours of parts of the image to form a new emerging shape. , which almost none of the participants could mentally reinterpret. Additionally, Reisberg and Chambers (1991) report a series of experiments using different types of ambiguous stimuli that again were not successfully reinterpreted by almost all participants except when hints were given.

Obrázek

Observing the stimuli in Figure 2.3, it can be plausibly claimed that these stimuli either do not really represent anything meaningful beyond their very shapes or they do so in a highly schematized way. For example, the “mirrored 2” could at best be described as a “heart on a plate”; an image that seems rather odd and unfamiliar. The point to make here is that these stimuli, in contrast to even a simple drawing like the duck-rabbit, seem much less realistic and meaningful, or simply less plausible to depict something familiar. There are studies which support this point that concrete “meaning” of stimuli plays a critical role in mental reinterpretation: Brandimonte, Hitch, and Bishop (1992a); Brandimonte, Hitch, and Bishop (1992b) have shown that figures that are easy to name are more difficult to mentally reinterpret than figures that are difficult to name.

Another difference that can be assumed between these stimuli and the duck-rabbit is that the latter is much more likely to be conceptually represented as a composition of parts (in this case natural to an animal) such as ears, head, eyes, and nose with the respective spatial relations between them. Whereas, the “heart on a plate” offers perhaps two parts and alphanumeric characters or simple geometric shapes might be represented holistically as consisting of just a single part3 3Such an assumed holistic representation of letters, numbers, and simple shapes might very well be due to our strong familiarity and daily exposure to them as suggested by Thomas (1999). Such a specific representation of letters and numbers is further supported by the neuropsychological findings of selective neglect of letters (Goldenberg, 1993). . The same observation applies also to the to-be-discovered second meaning of those stimuli. The new interpretations would similarly be conceptually represented by rather few mental concepts. For the mirrored numbers, the new interpretation is in fact simpler than the initial interpretation as only one half of the stimulus is considered and the new interpretation can be conceptually described trivially as “2”. The complexity of a previous and new interpretation is likely to affect mental reinterpretation. Concretely, it requires less effort to replace a trivial interpretation consisting of only very few mental concepts and at the same time it is of less effort to form a new interpretation that is of very low complexity, because it requires only very few “new” mental concepts to be identified.

The fact that the stimuli of Finke et al. (1989) were presented verbally and not as usual in such studies visually likely adds to the success of their mental reinterpretation. PIT assumes that the mental concepts underlying mental imagery are the product of the integration of all modalities, which means that in this case the mental concepts are derived from verbal input only and such a verbal description is naturally much less restricting in terms of concreteness and details than a visual presentation4 . Consequently, the plausibility of or converging evidence for a verbally given interpretation is less strong than that derived from a more detailed visual presentation given that everything else remains equal.

Summarizing, the stimuli (including both interpretations) that have been shown to be comparatively easy to mentally reinterpret would be 1) conceptually represented very simply, i.e., one to very few parts and spatial relations, 2) their resemblance to real objects is weak or non-existent, and 3) in case of a verbal presentation much less detailed and settled than for a visual presentation. All these aspects decrease the plausibility of the initial interpretation of these stimuli. The less plausible a current interpretation is, the more likely it becomes to find a more plausible alternative interpretation, i.e., successfully mentally reinterpret the mental image.

6.2.2 Why Mental Reinterpretation can be Improved

Section 2.1.1 reported the different factors that have been shown to significantly improve mental reinterpretation of stimuli that are otherwise hard to mentally reinterpret such as the duck-rabbit. These factors can be divided into four groups: 1) explicit hints about reference frame manipulation and identity of the to-be-discovered meaning, 2) training stimuli with the same reference frame reversals, 3) partitioning of the stimulus during presentation, and 4) articulatory suppression during presentation of the stimulus. Each of these four types of factors are discussed in the following.

Several studies reported that mental reinterpretation of ambiguous stimuli such as the duck-rabbit improve significantly when hints are provided during reinterpretation (e.g., Reisberg & Chambers, 1991; Hyman & Neisser, 1991). Such hints include: 1) hints about what to “see”, e.g., telling participants that they are looking for an animal, and 2) hints about the alternative reference-frame, e.g., “the front of the rabbit could be the back of another animal” or “the left side is the new top”. According to PIT’s explanation of why the duck-rabbit is hard to mentally reinterpret, these hints should help mental reinterpretation because they specify that (and to some extent how) the current interpretation should be discarded or altered. Reisberg and Chambers (1991) report experiments in which participants were presented drawings which were rotated versions of meaningful stimuli such as the shape of Texas. They discovered that the instruction to mentally rotate the stimulus did not lead any of the participants to discover the shape of Texas in their mental image. But the explicit hint to understand the left side of their mental image as the new top, in fact, led to successful mental reinterpretation for more than half of the participants. This striking result supports PIT’s explanation that hints are successful because they explicitly induce a re-structuring of the conceptual description of the current interpretation of the mental image. Whereas only mental rotation does not induce such re-structuring but only changes the orientation while keeping the current interpretation.

It has also been shown that participants that have been provided with training examples of ambiguous drawings which include the same reference-frame reversals as the later presented duck-rabbit show a significant increase in successful mental reinterpretation (Peterson et al., 1992). Again, such training likely increases the propensity of participants to discard the conceptual description of the current interpretation thus aiding the ability to draw an alternative interpretation.

Peterson et al. (1992), furthermore, showed that a partitioning of the ambiguous stimuli significantly increases the success of mental reinterpretation. In this study the ambiguous stimulus was presented in a piecemeal fashion so that participants had to mentally “glue” the presented parts together to get the complete stimulus. The fact that participants never perceived the full stimulus could likely lead to a lower plausibility of their interpretation than had they seen the full picture. This argument is similar to the one made previously about the study of Finke et al. (1989) who presented their stimuli verbally and not visually. In both cases the resulting initial interpretation of the stimulus should be less fleshed-out and should contain less fixed visual details than if one visually perceives the stimulus as a whole. This aspect should negatively affect the current interpretation’s plausibility and thus increase the likelihood of finding a new more plausible interpretation.

Brandimonte and Gerbino (1993) showed that the mental reinterpretation of the duck-rabbit significantly improves when participants are instructed to loudly say “lalala” during the initial presentation of the duck-rabbit. This procedure is termed articulatory suppression. This finding can be explained because the mental concepts which underlie mental images integrate multi-modal input. In the case of this study, the participants essentially link nonsense verbal input to the visual input of the duck-rabbit. Given that the conceptual description of the duck-rabbit contains information from both these sources, the overall converging evidence for the found interpretation is decreased as the verbal part simply does not fit with the interpretation “duck” or “rabbit”. Given a therefore lower plausibility of this interpretation the likelihood of replacing it with a more plausible interpretation is again increased.

6.2.3 Summary and Predictions

The phenomenon of mental reinterpretation is complex and includes many different aspects such as the different types of stimuli and the different types of hints. The interpretation process (as described in Section 3.1.6 and Section 4.2) is fundamentally involved in the explanation of this phenomenon. Also the interpretation process is at the heart of (categorical) perception and thus a hard problem for which no formal implementation exists (see Section 5.3.2). Accordingly, PIT’s explanations for the different aspects of mental reinterpretation have been made on a descriptive level. It is therefore not possible to make predictions as concretely as for mental scanning (Section 6.1) or eye movements (Section 6.3) for which the computational model can be applied directly. This section will thus provide a summary of the identified factors relevant for the success of mental reinterpretation and more general predictions that follow from that.

The explanations of PIT showed why mental reinterpretation is generally very hard unless either specific simple stimuli are used or additional hints and help is provided. The successful mental reinterpretation of a stimulus without additional hints depends mainly on the overall plausibility of the initial interpretation. The plausibility of the initial interpretation determines the success of mental reinterpretation in so far as that discarding the current interpretation (and replacing it with a new interpretation) becomes more likely the less plausible the initial interpretation is. Factors that contribute to the plausibility of an interpretation are: 1) how realistic the stimulus is and 2) how much converging evidence for the current interpretation exists.

The first point is illustrated in Figure 6.2. The duck-rabbit on the left side of the figure is predicted to be harder to mentally reinterpret than the classic duck-rabbit5 . This is because the duck-rabbit on the left side simply looks much more like an actual rabbit or duck (whatever the initial interpretation might be) and thus the initial interpretation will be more plausible and therefore harder to “overwrite”. This example also shows the second point, i.e., converging evidence for an interpretation, as the fur/feathers texture present in the left duck-rabbit supports the initial interpretation. Another way of varying converging evidence for ambiguous stimuli like the duck-rabbit is the presentation of additional information such as presenting sounds or verbal labels that would either support or provide evidence against one of the interpretations. For example, presenting the duck-rabbit stimuli together with a depiction of a pond, sounds made by ducks, or simply the subtitle “duck” should lead to decreased rates of mental reinterpretation6 . Another way of testing the above factors is to vary them for stimuli which have been shown to generally be mentally reinterpretable such as the “mirrored number” stimuli of Slezak (1995). These stimuli could be varied so that their parts resemble actual objects more clearly. Figure 6.3 shows some possibilities to make these stimuli more realistic and less abstract.
Help! I'm a multidimensional being trapped in a linear time-space continuum!

Uživatelský avatar
ATA
Příspěvky: 1602
Registrován: stř, 28. kvě 2008, 18:55
Bydliště: Litovel
Kontaktovat uživatele:

Re: WILD (visual stream)

Příspěvekod ATA » stř, 17. zář 2014, 23:20

Obrázek
Obrázek
Help! I'm a multidimensional being trapped in a linear time-space continuum!

Uživatelský avatar
ATA
Příspěvky: 1602
Registrován: stř, 28. kvě 2008, 18:55
Bydliště: Litovel
Kontaktovat uživatele:

Re: WILD (visual stream)

Příspěvekod ATA » čtv, 18. zář 2014, 12:58

Help! I'm a multidimensional being trapped in a linear time-space continuum!

Uživatelský avatar
ATA
Příspěvky: 1602
Registrován: stř, 28. kvě 2008, 18:55
Bydliště: Litovel
Kontaktovat uživatele:

Re: WILD (visual stream)

Příspěvekod ATA » čtv, 18. zář 2014, 23:27

ideas:

Foveola-centric reference frame for object visualization
Usual object manipulation distance
Whole image distance
Color pereceprion distance
Detail distance
View distance
Help! I'm a multidimensional being trapped in a linear time-space continuum!

Uživatelský avatar
ATA
Příspěvky: 1602
Registrován: stř, 28. kvě 2008, 18:55
Bydliště: Litovel
Kontaktovat uživatele:

Re: WILD (visual stream)

Příspěvekod ATA » stř, 24. zář 2014, 12:41

Help! I'm a multidimensional being trapped in a linear time-space continuum!

Uživatelský avatar
ATA
Příspěvky: 1602
Registrován: stř, 28. kvě 2008, 18:55
Bydliště: Litovel
Kontaktovat uživatele:

Re: WILD (visual stream)

Příspěvekod ATA » stř, 24. zář 2014, 23:26

Vědecké teorie vzniku mentálního obrazu:
Pictorial theory: the mental image is depictively represented in the visual buffer
Descriptive theory: the mental image is propositionally represented by amodal descriptions
Enactive theory: the mental image is not represented directly. Instead the processes that lead to the experience of mental imagery are encoded in the respective schemata

The spatio-analogical character of mental imagery refers to the fact that behavior in mental imagery is often analogical to behavior expected for an actual picture. The mental scanning effect is an example that shows this spatio-analogical character of mental imagery. There are several more examples, e.g., inspecting “smaller” parts of a mental images takes longer than inspecting “bigger” parts (for an overview of similar studies, see Kosslyn, 1980). The three theories explain this spatio-analogical character of mental imagery as follows:

Pictorial theory: The spatio-analogical character of mental imagery results from the spatio-analogical structure of the visual buffer which holds the depictive mental image. That is, the processing of the mental image is determined by the structure of the mental representation.
Descriptive theory: The spatio-analogical character results from the non-functional application of one’s tacit knowledge. That is, applying the knowledge of what perceiving the to-be-imagined entity would be like and subconsciously emulating of these properties, e.g., expected reaction time patterns.
Enactive theory: The employment of the processes of visual perception including non-mental processes such as eye movements give mental imagery the same spatio-analogical properties that the visual system has, e.g., longer attention shifts (such as saccades) take more time.

The three theories, furthermore, differ in their assumption of what mental imagery is:

Pictorial theory: mental imagery is the processing of the mental image in the visual buffer using processes of visual perception. This understanding is based on the assumption that the visual buffer is similarly used during visual perception to provide a mental representation of what is currently perceived.
Descriptive theory: mental imagery is the processing of the respective amodal descriptions which represent the mental image. These descriptions are not processed by modality-specific mechanisms such as processes of visual perception. Mental imagery is further defined by the concurrent (non-functional) application of one’s tacit knowledge about how the content of the current mental image would be perceived in visual perception. Tacit knowledge causes the characteristic behavior, e.g., reaction time patterns, of mental imagery. If descriptions are processed without the application of tacit knowledge, this would be considered general cognitive processing and not mental imagery.
Enactive theory: mental imagery arises through the employment of those schemata which are otherwise used to perceive real-world entities. It is those entities which are mentally imagined when these schemata are employed without fitting real-world stimuli. That is, the re-enactment of the perception of an entity corresponds to the mental imagination of that entity
Jako základ používám Perceptual Instantiation Theory (PIT) která je založena Enactive theory ale obashuje i prvky z pictoral a deescriptive theory.

The Perceptual Instantiation Theory http://cosy.informatik.uni-bremen.de/si ... magery.pdf

The enactive theory emphasizes the role of the attentional and perceptual processes directed at external stimuli, e.g., the role of eye movements, in perception and mental imagery. In contrast, the pictorial and the descriptive theory are generally not concerned with these processes and do, instead, assume mental imagery to be realized on a “higher” level. That is, the processing of mental representations by mechanisms aimed not at external entities but at the mental representation of entities.

Accordingly, the understanding of visual perception of the enactive theory differs from that of the other two theories. Perception in the enactive theory consists of several different specialized perceptual instruments which are selectively used to retrieve specific information from the environment. In the other theories, in contrast, perception seems to be assumed as a much more generic process whose major task is providing input to the visual buffer (in the pictorial theory) or to the propositional descriptions (in the descriptive theory). The relevant processing of visual perception and mental imagery is accordingly based on these resulting mental representations.

This view of visual perception means that recognition is not a comparison or pattern-matching process working on a mental representation of what is currently being perceived. But recognition is the successful application of specific perceptual actions to the external stimulus, e.g., the eye movements and their respective feedback lead to the recognition of a square. After the perceived object has been interpreted as a square, much information is discarded and an abstract conceptual description of the object remains in long-term memory. That is, if one remembers the object in question after some time, the fact that it was, for example, a red small square, remains, but many details, such as the exact size, location, orientation, or color, are often missing or have been replaced by generic information. The information that has been lost by this abstraction comprises the low-level information that was made available by the perceptual actions. This includes, specifically, the coordinates of the object in an ego-centric reference frame, through which information about concrete size, orientation, depth, location, and visual features of the object can be determined. Such information is available during and shortly after the perceptual process on that level of granularity that the visual system is capable of perceiving and distinguishing. This information is referred to as perceptual information. In contrast, the abstracted conceptual memory of that object – red, small, square – could be seen as qualitative information, but will be referred to as conceptual information, or simply mental concepts.

Visuo-Spatial Long-Term Memory
The visuo-spatial long-term memory (abbreviated VS-LTM) constitutes the procedural knowledge of how to look at the world in order to recognize entities, properties, and relations. For this purpose the VS-LTM provides two mappings: 1) a mapping of perceptual information onto mental concepts, and 2) a mapping of mental concepts onto perceptual actions. These mappings are acquired procedural knowledge and are continuously adapted.



The currently identified or partially identified mental concepts and the temporarily available corresponding perceptual information determine the perceptual action that will be executed next. This step is realized by the other mapping provided by the VS-LTM: the mapping of mental concepts onto perceptual actions. It is assumed that the strategy of choosing a perceptual action in a given situation follows the principle of maximum information gain. That is, the strategy is to choose that perceptual action which is expected to give the maximum gain of information about what the perceived object or scene is. Such strategies are considered in vision research for scene and object recognition (e.g., Schill, Umkehrer, Beinlich, Krieger, & Zetzsche, 2001). For the example of the partially identified mental concept square, i.e., the location and orientation of three edges have already been perceived, the next perceptual action would be an attention shift towards an anticipated fourth edge to gather support for the hypothesis that the object in question is indeed a square. This attention shift might be another saccade. The planning of that saccade takes into account the available perceptual information of the already known edges. That is, the to-be-attended-to fourth edge is anticipated to have a location and orientation fitting with the already known edges. The saccade is then executed towards this specific location. Given that the edge is found at the respective location, the next chosen perceptual action would retrieve the orientation and other visual features. The perceptual feedback, i.e., the location provided by the saccade and information about the orientation, lead to the full identification of the mental concept square.

The mapping of mental concepts onto perceptual actions is also a many-to-many mapping. That is, one mental concept can be identified by several different (sets of) perceptual actions and different mental concepts can be identified by employing the same perceptual actions. For example, to check for the fourth edge of a square, both an appropriate saccade and an appropriate head movement are possible. Furthermore, information about distance as well as information about direction between two given objects can be retrieved by the same perceptual action such as a saccade.

* pridat akce z koncepty

Perceptual Actions
It is an assumption of PIT that almost all perception is mediated by and thereby connected to respective perceptual actions. Examples of perceptual actions of visual perception include saccades, micro-saccades, head and body movements, adjusting the focal length of the lens as well as covert actions such as covert attention shifts. Different types of information are retrieved using different perceptual actions. For example, information about locations and spatial relations can be retrieved by saccades, while smooth pursuit is used to track the movement of an object, and adjusting the focal length of our lenses gives information about depth.

Mental Concepts
The memory of a previously perceived scene corresponds to a conceptual description of that scene in conceptual long-term memory (C-LTM). Conceptual descriptions consist of mental concepts. Mental concepts include spatial relations (e.g., left-of, close), objects (e.g., square, house), and properties (e.g., red, big). The C-LTM comprises all mental concepts and associative links between them. The C-LTM can be understood as what is often referred to as declarative or associative memory (Anderson, 2005). The mental concepts of PIT have two important properties: 1) they are grounded symbols and 2) they incorporate input from all modalities. These two properties will be elaborated in the following.

*modou obsahovat mnohem přesnější informace

The mental concepts of PIT are grounded symbols in that they function as hubs linking to perceptual actions. The linked perceptual actions are those which are used for the perception of the entity that the respective mental concept represents. That is, for example, the mental concept of the relation left of comprises the different ways of perceiving the relation left of such as certain eye movements, hand movements, attending to certain sound patterns, and hearing the words “left of” in a sentence. The so-defined mental concepts of PIT differ from symbols as often used in cognitive science and artificial intelligence (for example, ACT-R (Anderson et al., 2004), physical symbol system (Newell, 1990), or mentalese (Fodor, 1975)), because 1) they do not contain the semantics of the entity they represent, and 2) they do not directly reflect properties of the entity they represent. The semantics of a mental concept, that is, what the mental concept means to the organism, corresponds not to the processing or the activation of the mental concept, but the semantics are manifested in the process of executing the linked perception actions. That is, the semantics of an entity are the perception of that entity, i.e., what seeing, touching, or otherwise perceiving the entity is like. The mental concepts also do not directly reflect the properties of the represented entity. Consider, for example, that a depictive mental representation of an entity does preserve and thus reflect properties of the represented entity (e.g., Kosslyn, 1994). The properties of an entity instead become available by the perceptual feedback of the perceptual actions in visual perception. In mental imagery, as it will be discussed later, the employment of the linked perceptual action generates a perceptual instance of the represented entity which makes some of the properties of the entity available.
* sít konceptů, priming ,relevance

A set of mental concepts describing a scene incorporates the input of all modalities. That is, the perception of, for example, a cheese contains not only the visual and spatial information of it conveyed via visual perception but also the smell that was perceived and its texture and feel when it was touched. The resulting mental concepts of the perception through the different modalities are combined in one final conceptual description of that cheese. Importantly, also subtle and fully subconscious information such as that communicated via different demand or task characteristics (Orne, 1962) is assumed to be included in the final conceptual description.
The different modalities can also give conflicting input as in, for example, the McGurk effect (McGurk & MacDonald, 1976). The McGurk effect is an example of sensory integration. When seeing a video of someone saying “ga” without sound but at the same time hearing the sound “ba”, we perceive the person in the video actually saying “da” which is a mixture of those two sounds. Conflicting mental concepts can be part of the conceptual description of a scene. When this conceptual description is processed during the mental imagination of the scene, these conflicting mental concepts might be integrated to make the mental image of the scene consistent.

The process of mental imagery starts with a conceptual description of what is to be imagined. That is, mental imagery starts with the end product of visual perception. A conceptual description of a scene consists of a set of mental concepts such as house, left of, tree. As discussed in Section 3.1.5 mental concepts consist of links to those perceptual actions which are used to identify the mental concepts, i.e., they are used to look at that thing which the respective mental concept represents. In mental imagery these links from mental concepts to perceptual actions are used to create an instance of perceptual information that corresponds to the respective set of mental concepts. The mental concepts are successively mapped onto perceptual actions which are then executed either overtly, e.g., spontaneous eye movements, or covertly. The execution yields perceptual information, for example, information about the change of gaze position. This process of picking and employing perceptual actions for a given mental concept in order to retrieve perceptual information is referred to as instantiation. The term instantiation is used because the perceptual information which is made available by the employment of perceptual actions represents one (perceptual) instance of the mental concepts that conceptually describe the mental image. The perceptual information made available through instantiation is mapped onto mental concepts by the VS-LTM just as it is the case in visual perception. The perceptual information and the mental concepts that have been identified based on it, influence the instantiation of further mental concepts. Again, similar to visual perception, from all identified mental concepts and their respective perceptual information, an interpretation is drawn and held in short-term memory. The interpretation is the most plausible subset of all identified mental concepts with their perceptual information. This interpretation in short-term memory constitutes the mental image. The perceptual information of the mental image held in short-term memory can be used for further processing, e.g., inferring new information such as previously not identified spatial relations.[/i]
Help! I'm a multidimensional being trapped in a linear time-space continuum!

Uživatelský avatar
ATA
Příspěvky: 1602
Registrován: stř, 28. kvě 2008, 18:55
Bydliště: Litovel
Kontaktovat uživatele:

Re: WILD (visual stream)

Příspěvekod ATA » stř, 24. zář 2014, 23:56

Help! I'm a multidimensional being trapped in a linear time-space continuum!

Uživatelský avatar
ATA
Příspěvky: 1602
Registrován: stř, 28. kvě 2008, 18:55
Bydliště: Litovel
Kontaktovat uživatele:

Re: WILD (visual stream)

Příspěvekod ATA » čtv, 25. zář 2014, 11:48

Kvalita obrazu(vjemu) vs. Zkreslení informace
Před samotným pokusem se někam dostat nebo něco vnímat by se mělo určit jestli nám jde o co nejpřesnější vnímání informace z minimálním zkreslením nebo naopak o silné senzorické vjemy například kvalitu obrazu .Je možné mít jak nezkreslenou informaci tak kvalitní obraz ale dosažení tohoto stavu je obtížné a vwe většině případu bude třeba nějaký kompromis mezi oběma.

Tvorba mentálních obrazů, snů, LD... funguje obráceně než naše běžné fyzické vnímání (obraz-koncept vs koncept-obraz).
Například pokud se podíváte na tento obrázek:
Obrázek Tak se identifikuje kontrast,tvar, barva.. postupně se dostaneme z identifikací až k tomu že je to strom, je to jehličnan , smrk tak že výsledkem budou koncepty z různou úrovní abstrakce.
(o tom jak probíhá identifikace bude pude podrobněji v dalších částech)

Te si přestavte opačnou situaci někdo vám zadá at si vizualizujete strom.Co vidíte/vnímáte? Jeden z faktoru co ovlivní výsledek je i to jak vám záleží na přesnosti.

Výsledkem muže byt pouze abstraktní představa stromu která nemá žádnou konkretní podobu, je to spíše popis co musí splňovat objekt aby byl pokládán za strom ale tento popis je vyjádřitelný slovy jen vile omezeně. Pokud to vyjádříme slovy tak jsem na další úrovni již omezené jazykem. Většina lis pude ještě mnohem dál a bude mít představu reálného stromu ne stromu na obrázku. Postupně to muže jít přes třeba tip stromu tím vznikne další omezení málo kdo si třeba představí palmu.Postupně se muže dále omezovat až na konkretní podobu stromu z danou barvou texturou , pozici , velikostí.

Je to v pár věcech podobné jako když do vyhledávače zadáte strom výsledkem budou všechny možné reprezentace stromu a toho co to strom je druhá možnost je to tlačítko „mi feealing lucky“ ketré vybere nejpravděpodobnější možnost a tu ukáže .
Obrázek
Obrázek
Figure 4.2: The formal framework of PIT. The mental imagination of a scene starts with 1) the retrieval of a set of mental concepts from C-LTM which conceptually describe the scene; 2) these mental concepts are successively instantiated with perceptual information by the cyclic process of select-execute-identify; 3) an interpretation is drawn from all identified mental concepts with their instances of perceptual information; 4) this interpretation constitutes the mental image of the scene.
Obrázek
Obrázek
Help! I'm a multidimensional being trapped in a linear time-space continuum!

Uživatelský avatar
ATA
Příspěvky: 1602
Registrován: stř, 28. kvě 2008, 18:55
Bydliště: Litovel
Kontaktovat uživatele:

Re: WILD (visual stream)

Příspěvekod ATA » čtv, 25. zář 2014, 12:41

WILD a LD
U metody WILD a LD nám jde hlavně o kvalitu obrazu a na kvalitu překladu konceptu se tu nebere ohled.

OOBE
Zde je to hodně o názorech a konkrétním nastavení ve většině případů je to ale nastaveno spatně na základě chybných předpokladů jako :
To co vidím je realita.
Když se dostanu z těla vše uvidím.
Realné věci se nemění před očima.
Tyto předpoklady často vedou k situaci kdy nutíme podvědomí vytvořit konkrétní a neměnný obraz .

Šamanské cestování
Je někde na pul cesty mezi AC a LD jde tam již o zjískání konkretních informací vetšinou jsou podány hodně simbolickou formou.

AC
Každej si pod tím představuje něco jiného co je vetšinou společné je zachování ego-centického vnímání jsme přitomni v prostředí co vnímáme, informace mohou byt jakoukoli formou od konkrétních (obrazy,senzorické vjemy) a až po velice abstraktní.Většinou silně ovlivněno vírou a názory jak by to vnímání mělo vypadat.

Remote viewing
Zde již vetšinou nejsme v prostředí jen ho na dálku pozorujeme.Stále je tu ještě snaha použivat normální styl vnímání jako použiti zraku na vidění.

Vnímání konceptu
Vetšinou pomocí jazyka

Vědění bez vnímání
Přímé vnímání abstraktních konceptu bez jejich převodu do senzorických vjemů
Help! I'm a multidimensional being trapped in a linear time-space continuum!

Uživatelský avatar
ATA
Příspěvky: 1602
Registrován: stř, 28. kvě 2008, 18:55
Bydliště: Litovel
Kontaktovat uživatele:

Re: WILD (visual stream)

Příspěvekod ATA » čtv, 25. zář 2014, 14:10

Záměr něco mentálně vidět a jeho neurčitost
Při bežném vnímání fyz. reality nemáme moc šanci si uvědomit že zrak je zkutečnosti modulární proces a co to vlastně znamená něco vidět.
Pokud si něco představujeme tak tyto moduly pracují značně nezávisle.

http://idealab.ucdavis.edu/IST/ISTF08/l ... 9vhtml.htm
http://idealab.ucdavis.edu/IST/ISTF08/l ... 0vhtml.htm

Zpracování zrakových informací v mozku se děli na 2 hlavní proudy jeden z nich se stará o identifikaci objektů a ten druhý o to jak s nimy manipulovat.
Two visual systems re-viewed
http://www.ncbi.nlm.nih.gov/pubmed/18037456

To be able to grasp an object successfully, for example,
it is essential that the brain compute the actual size of the object,
and its orientation and position with respect to the observer
(i.e. in egocentric coordinates). We also argued that the time
at which these computations are performed is equally critical.
Observers and goal objects rarely stay in a static relationship
with one another and, as a consequence, the egocentric coordi-
nates of a target object can often change radically from moment
to moment. For these reasons, it is essential that the required
coordinates for action be computed in an egocentric framework
at the very moment the movements are to be performed.
Perceptual processing needs to proceed in a quite different
way. Vision for perception does not require the absolute size of
objects or their egocentric locations to be computed.
In fact, such
computations would be counter-productive. It would be better to
encode the size, orientation, and location of objects relative to the
other, preferably larger, objects that are present. Such a scene-
based frame of reference permits a perceptual representation of
objects that transcends particular viewpoints, while preserving
information about spatial relationships (as well as relative size
and orientation) as the observer moves around.


These considerations led us to predict that normal observers
would show, under appropriate conditions, clear differences
between perceptual reports and object-directed actions when
interacting with pictorial illusions, particularly size-contrast illu-
sions. This counter-intuitive prediction was initially based on the
simple assumption that the perceptual system could not avoid
computing the size of a target object in relation to the size of
neighbouring objects, whereas visuomotor networks would need
to compute the true size of the object.
This prediction was con-
firmed in a study by
Aglioti, Goodale, and DeSouza (1995)
which showed that the scaling of grip aperture in-flight was
remarkably insensitive to the Ebbinghaus illusion, in which a
target disc surrounded by smaller circles appears to be larger
than the same disc surrounded by larger circles. In short, max-
imum grip aperture was scaled to the real not the apparent size
of the target disc.

According to our two visual systems model, vision for action
works only in real time and is not normally engaged unless the
target object is visible during the programming phase, that is
when bottom-up visual information is being converted into the
appropriate motor commands. When there is a delay between
stimulus offset and the initiation of the grasping movement,
the programming of the grip would be driven by a memory of
the target object that was originally derived from a perceptual
representation of the scene, created moments earlier by mecha-
nisms in the ventral stream

Thus, we
would predict that memory-guided grasping would be affected
by the illusory display, because the stored information about the
target’s dimensions would reflect the earlier perception of the
illusion. In fact, a range of studies has shown that this is exactly
the case In the case
of the dorsal stream this is not so: indeed the coding of the target
has to be as far as possible absolute, and needs to be referred to
an egocentric rather than a scene-based framework
. Non-target
visual information needs to impact dorsal-stream processing
dynamically, thereby influencing the moment-to-moment kine-
matics of the action. It seems likely that this happens without
the visual coding of target information being itself modulated:
in other words that both target and non-target information each
modulate motor control directly and quasi-independently

Matters are quite different in the dorsal stream,
where the peripheral field is relatively well represented. Indeed
some dorsal-stream areas, such as the parieto-occipital area
(PO), show almost no cortical magnification at all, with a large
amount of neural tissue devoted to processing inputs from the
peripheral visual fields

Obrázek
Proud pro akci
- je egocentrický = pohled z 1.os ,z těla , ve vztahu k tělu
- vzdálenosti a velikosti jsou absolutní = přesné hodnoty
- je dále rozdělen na proud pro natáhnutí a proud pro chycení.

Natáhnutí a chycení
Natáhnutí řeší kde je objekt v prostoru a jeho orientaci
Chycení řeší jeho přesný tvar a velikost
Different evolutionary origins for the Reach and the Grasp: an explanation for dual visuomotor channels in primate parietofrontal cortex
http://journal.frontiersin.org/Journal/ ... 00208/full

The Reach is mediated by a dorsomedial pathway and transports the hand in relation to the target’s extrinsic properties (i.e., location and orientation). The Grasp is mediated by a dorsolateral pathway and opens, preshapes, and closes the hand in relation to the target’s intrinsic properties (i.e., size and shape).

Obrázek
Obrázek

A number of patients with damaged visual inputs to the Grasp, but not the Reach, pathway have been described (50, 51). These patients have no problem reaching to the location of a visual target and consistently touch it on the first attempt; however, they use an open hand to do so and only close their digits to grasp the target after touching it. Thus, these patients seemingly adopt a modified Touch-then-Grasp strategy. They use vision to determine the target’s extrinsic properties (location) but are unable to use vision to determine the target’s intrinsic properties (size and shape) and thus cannot preshape the hand to Grasp prior to target contact. Instead they rely on haptic cues after target contact to shape their digits to the contours of the target in order to Grasp it.

---
Cavina-Pratesi and colleagues (52) describe the reverse condition, in which a patient cannot perform a visually guided Reach but can perform a visually guided Grasp. The patient, M.H., suffered an anoxic episode, disrupting visual inputs to the Reach but not the Grasp pathway. M.H. accurately opens, preshapes, and closes his hand to Grasp a visual target, but only if the target is located adjacent to his hand; i.e., if he doesn’t have to Reach for it. If he does have to Reach for it, he must first locate it by touch before shaping his hand to Grasp it: “Presumably M.H., wittingly or unwittingly, compensates for the direction and distance errors resulting from his damaged visual reaching network, by habitually opening his hand widely: the wider the hand aperture, the higher the probability of successfully acquiring the object.” M.H.’s visually guided Reach movements are inaccurate regardless of whether the movement is directed inward (toward his body) or outward (away from his body), indicating that his deficit is related to visual guidance of the Reach and not the location of the target within egocentric space. Thus, M.H. can use vision to guide his hand in relation to the intrinsic (size and shape) but not extrinsic (location) properties of a target.
Obrázek
Obrázek
Help! I'm a multidimensional being trapped in a linear time-space continuum!

Uživatelský avatar
ATA
Příspěvky: 1602
Registrován: stř, 28. kvě 2008, 18:55
Bydliště: Litovel
Kontaktovat uživatele:

Re: WILD (visual stream)

Příspěvekod ATA » pát, 26. zář 2014, 00:37

Předpoklady při vizualizaci

Zdá se že mají ruzný původ od evolučních , fyzilogických po názory , víry a sugsece .

Jedním z předpokladů který se povedlo identifikovat je gravitace.Tento předpoklad napřiklad stěžuje vizualizaci pevného předmětu jen tak v prostoru protože předpokald říklá že by na nej měla působyt gravitace a měl by spadnout.Proto bude snažší vizulizovat předmet na pevném povrchu než v prostoru. Dá se obejít několika způsoby nebo přímo vypnout.


Dekonceptualizace - Praxe

Použít ruku a snažit se k předmětu natáhnout a chytnout ho do ruky. Dá se to i rozdělit natáhnutí určí polohu a snaha o chycení určí přesně tvar a velikost.Tento proces donutí koncept zaujmout jednu konkretní podobu (o tom jak a proč to funguje je v teorii).Pro začátek je nejlepší představit si vlastní ruku napojenou na aktulně vnímané tělo a v predtavě ji natáhnout ze záměrem chytit předmet.Předmět by mel zaujmout přesný tvar a velikost ve vzdálenosti natažené ruky.Pokud jde o velký objekt třeba slon tak po doteku uvidíme jen jeho malou část zatím se ukázalo jako nesnadní od něj v představě kousek odejít.Da se použit i metoda kde ruka nebude poropojená z aktulně vnímaným tělem.Po troše praxe bude již stačit záměr natáhnout a chytnout a představa ruky již nebude potřeba také lze použít záměr z předmětem manipulovat da se dokonce oddělit jednotlivé prvky a měnit pozici konceptu v prostoru aniž by mel další atributy jako přesnou velikost,tvar,barvu... Výběr předmětu muže byt taky učiněn jakoby myší kde se vybere oblast/okno pokud je přidán záměr manipulace (jde označit i 3D obast)

Metodu jde použit jak na urovni kde máme jen koncept bez obarazu tak rozmazaný nebo velice nekvalitní obarz keterý nemá přesne určené atributy.

Pokud nejsou vypnuty předpokady ketré ovlyvnují vizulizaci je lepši vizualizovat jako 2D v okně (vybrané oblasti keterá je jasně ohraničena/určena) okno muže byt uchyceno na ruzné referenční rámce jako třeba presné místo v prostoru , vůči tělu , očím , hlavě, konkretnímu predmětu...

Použíti okna má obrovské vyhody v tom že obcházi většinu předpokladu a možných kolizí.Obraz v okně má mnohem méně omezení protože tam nutně neplatí fyz zákony podobá se spíše obrazovce PC nebo rozhraní simulátoru.

Obrázek
Rozhraní simulátoru ovládano spíše přimo záměrem ale je možné si zobrazit i ovládací prvky.Je vhodé se pro inspiraci podívat na nějaký podobný Pc pogram jaké má funkce a co vše muže z obrazem dělat.
Co sem zrovna zkoušel bylo určeni vektoru a intezity gravitace ve vizulizovaném okně kde to ovlivnovalo pohyb kostky.Práce v pogramu pomuže zbavit se omezeni z fyz reality ketre aplikujeme bežne u vizulizace jako nemožnost prolínání predmětu , fyz realita také neumožnuje nativně práci ve vrstvách a podminky jejich interakce i když náš senzorický systém tak pracuje .

Použiti oken také omezuje strach z prolínáni fyz a nefyz reality protože prostor kde se muže promítat a je jasně ohraničen.

Gesta na ovládáni obrazu

Roztočeni obrazu pohybem prstů do stran "mávnutí" dobrej zpusob jak si objekt prohlidnout ze všech stran mirne točeni jej take stabilizuje

Změna obrazu-výber z dalších možnosti reprezentace pohyb zápěstim nahoru nebo dolu kliknuti na vybraný,rychlost gesta ovlivnuje rychlost změny (díky mnoha omezením není snadné zobrazit možnosti vedle sebe)

Chycení jakoby dovnitř a mirne zhora -uchopi objekt a umožni ho vytáhnout z okna dobrej způsob jak z něj udělat 3D
Help! I'm a multidimensional being trapped in a linear time-space continuum!

Uživatelský avatar
ATA
Příspěvky: 1602
Registrován: stř, 28. kvě 2008, 18:55
Bydliště: Litovel
Kontaktovat uživatele:

Re: WILD (visual stream)

Příspěvekod ATA » stř, 28. led 2015, 00:01

DIRECT-CONTROL-OF-THE-RETINAL-FIELD

http://www.scribd.com/doc/107189821/DIR ... HREE-CASES

*afterimage after visualization using retinal field (closed eye viz. , open and look to white paper)
Help! I'm a multidimensional being trapped in a linear time-space continuum!

Uživatelský avatar
ATA
Příspěvky: 1602
Registrován: stř, 28. kvě 2008, 18:55
Bydliště: Litovel
Kontaktovat uživatele:

Re: WILD (visual stream)

Příspěvekod ATA » úte, 08. bře 2016, 12:13

Koncepty jsou nezávislé na smyslech
Explicit encoding of multimodal percepts by single neurons in the human brain.

Different pictures of Marilyn Monroe can evoke the same percept, even if greatly modified as in Andy Warhol's famous portraits. But how does the brain recognize highly variable pictures as the same percept? Various studies have provided insights into how visual information is processed along the "ventral pathway," via both single-cell recordings in monkeys and functional imaging in humans. Interestingly, in humans, the same "concept" of Marilyn Monroe can be evoked with other stimulus modalities, for instance by hearing or reading her name. Brain imaging studies have identified cortical areas selective to voices and visual word forms. However, how visual, text, and sound information can elicit a unique percept is still largely unknown. By using presentations of pictures and of spoken and written names, we show that (1) single neurons in the human medial temporal lobe (MTL) respond selectively to representations of the same individual across different sensory modalities; (2) the degree of multimodal invariance increases along the hierarchical structure within the MTL; and (3) such neuronal representations can be generated within less than a day or two. These results demonstrate that single neurons can encode percepts in an explicit, selective, and invariant manner, even if evoked by different sensory modalities.
Koncept reprezentuje různé konkrétní podoby
Invariant visual representation by single neurons in the human brain.
It takes a fraction of a second to recognize a person or an object even when seen under strikingly different conditions. How such a robust, high-level representation is achieved by neurons in the human brain is still unclear. In monkeys, neurons in the upper stages of the ventral visual pathway respond to complex images such as faces and objects and show some degree of invariance to metric properties such as the stimulus size, position and viewing angle. We have previously shown that neurons in the human medial temporal lobe (MTL) fire selectively to images of faces, animals, objects or scenes. Here we report on a remarkable subset of MTL neurons that are selectively activated by strikingly different pictures of given individuals, landmarks or objects and in some cases even by letter strings with their names. These results suggest an invariant, sparse and explicit code, which might be important in the transformation of complex visual percepts into long-term and more abstract memories.
Vnímání a vizualizace má stejný neurální podklad
Imagery neurons in the human brain.
Vivid visual images can be voluntarily generated in our minds in the absence of simultaneous visual input. While trying to count the number of flowers in Van Gogh's Sunflowers, understanding a description or recalling a path, subjects report forming an image in their "mind's eye". Whether this process is accomplished by the same neuronal mechanisms as visual perception has long been a matter of debate. Evidence from functional imaging, psychophysics, neurological studies and monkey electrophysiology suggests a common process, yet there are patients with deficits in one but not the other. Here we directly investigated the neuronal substrates of visual recall by recording from single neurons in the human medial temporal lobe while the subjects were asked to imagine previously viewed images. We found single neurons in the hippocampus, amygdala, entorhinal cortex and parahippocampal gyrus that selectively altered their firing rates depending on the stimulus the subjects were imagining. Of the neurons that fired selectively during both vision and imagery, the majority (88%) had identical selectivity. Our study reveals single neuron correlates of volitional visual imagery in humans and suggests a common substrate for the processing of incoming visual information and visual recall.
----
Retinotopic organization of visual mental images as revealed
by functional magnetic resonance imaging

http://www.micheldenis.fr/wp-content/up ... 04-CBR.pdf
Vizualizace je limitovaná neurálním podkladem
*přesnost v periferním vidění
Mental imagery acuity in the peripheral visual field.
Finke RA, Kosslyn SM.
Abstract

Subjects made judgements of resolution on two small dots that they either imagined or acutally observed at horizontal and vertical positions away from the point of eye fixation. As the distance between these two dots increased, the size of fields of resolution in imagery increased, in proportion to increases in the size of fields of resolution in perception. For vivid imagers, fields of resolution in imagery were the same size as those in perception, whereas for nonvivid imagers, fields of resolution in imagery were smaller than those in perception. In addition, fields of resolution in imagery and perception were virtually identical in shape, exhibiting similar horizontal eccentricity and vertical asymmetry. Fields within which attention can be distributed in imagery were also measured by having subjects make judgements of resolution on pairs of dot patterns imagined simultaneously on opposite sides of the point of eye fixation. These fields were smaller than fields of resolution for images of single dot patterns and were circular, as opposed to elliptical. These results suggest that peripheral acuity in visual imagery is limited by the same types of neural constraints that limit peripheral acuity in visual perception.
Help! I'm a multidimensional being trapped in a linear time-space continuum!


Zpět na “Výzkum”

Kdo je online

Uživatelé prohlížející si toto fórum: Žádní registrovaní uživatelé a 1 host