Görkem Er

Some notes I gathered from reading some articles over the summer22. This series of articles are, I think, about retinal vs perceptual processing and gestalt grouping.

• Sheinberg, D. L., & Logothetis, N. K. (2001). Noticing Familiar Objects in Real World Scenes: The Role of Temporal Cortical Neurons in Natural Vision. The Journal of Neuroscience, 21(4), article
• Authors reported object-sensitive cells in the anterior regions of the temporal lobes (of monkeys) which appears to transform perceived wholes to behavior.
• Activity drops (performance is better) while looking for a target embedded with natural background. Like competition and surround inhibition

• Coren, S., Porac, C., & Theodor, L. H. (1986). The effects of perceptual set on the shape and apparent depth of subjective contours. Perception & Psychophysics, 39(5), A
• Authors argue that, instead or in addition to structural explanations, cognitive mechanisms (like Expectations and observer set) also affect whether the illusory contour is seen or not.

• Julesz, B. (1981). Textons, the elements of texture perception, and their interactions. Nature, 290(5802). A
• Authors refer some special local features (called textons) that allow distinguishing iso-second-order textures (think displays that "look" the same).
• Those are kinda defined by: the number of terminators, and stats like aspect-ratio, and contrast (measured by elongated blobs?).
• Nice background about preattentive attention being parallel, and attentive being focal and serial.

• Rock, I., & Anson, R. (1979). Illusory Contours as the Solution to a Problem. Perception, 8(6). A
• They investigated how cues like collinearity ve incompletion affect the formation of illusory contours (also referred to as subjective contours).
• Sick reserach designs.
• Stripes in the background help eliminate the illusion (seeing a triangle in the foreground, stripes eliminate the "illusion" of thinking there is a triangle with the same background color)).

∅ Stripes in the background (b) reported to be reducing the the formation of Kanizsa triangle (illusory triangle seen at (a), I kinda see a triangle in the stripes example :/ ). Taken from the above referenced article, I hope this is inline with fair use.

• Wang, L., Weng, X., & He, S. (2012). Perceptual Grouping without Awareness: Superiority of Kanizsa Triangle in Breaking Interocular Suppression. PLoS ONE, article (A)
• They kept the local features of an image (all "consists of the same local Pacmen") while one of the image forming a Kanizska triangle and showed that one with Kanizska triangle breaks suppression time faster.
• Participants engaged in dual task and results showed that structural changes in the background made them more sensitive (measured by d-prime) in detecting changes in local features.
• Interesting to me because "grouping" is linked with awareness or involves some process that helps break interocular suppression.

• Stein, T., Kaiser, D., & Peelen, M. V. (2015). Interobject grouping facilitates visual awareness. Journal of Vision, A
• Objects that are grouped by previous experience (like plates are often located on a table rather than vice versa) break suppression earlier/faster (breaks the continuous flash suppression (CFS) paradigm).
• One direct example, the sink, and the mirror have a bottom-top spatial configuration, their relationships are the key here, the authors say.
• Simple and direct findings, neat study.

• Fischer, R., & Miller, J. (2008). Differential redundancy gain in onset detection versus offset detection. Perception & Psychophysics, 70(3), A #redundancy_gain
• Nice! Pretty neat results
• Stimuli appearance vs stimuli disappearance involves different processes. But redundancy gain literature only studied on-set time detection (stimuli appearance). They asked: can redundancy gain effects be applied to off-set stimuli detection performance?
• On-set stimuli detection is faster when there is a redundant flash (two-identical), same for the detection of off-set.
• Also, on-set detection responses are faster on overall (compared to off-set), and less forceful (e.g. lighter keyboard presses when responding).

• Rock, I., & Anson, R. (1979). Illusory Contours as the Solution to a Problem. Perception, 8(6), A
• Can grouping by similarity & proximity occur when participants don't attendt to it?
• Gestalt people say that this grouping should occur very early in the visual system (after retinal processes). They say the intention to search can be considered as attention, none of the previous research examines perception under conditions of inattention (they adopted the term non-attentional to describe visual processing uner conditions of inattention).
• Texture segregation: searching for a group of features
• Pop-out experiments: searching for an odd one.
• If things occur under inattention = processed in earliest visual processing.
• *this made me think about how our motion-grouping paradigm can be a test of how unattended motion direction influences grouping.

• Rao, R. P. N., & Ballard, D. H. (1999). Predictive coding in the visual cortex: A functional interpretation of some extra-classical receptive-field effects. Nature Neuroscience, A
• Error-detecting neurons - quantifying how "surround" can predict the "center".
• They start with the question of why neurons' activity drops when stimuli move out of their RF.
• If things occur under inattention = processed in earliest visual processing.
• RF can be an emergent property. Predictions from the higher-level regions are fed to lower-level, processing, neurons, and some other neurons represent that prediction errors, I think.
• "Residual error detectors, signaling the difference between an input signal and its statistical prediction."
• They formed a multi-layered model and tested it on natural images. For example, when Level 2 is removed, activities in neurons at level drop down, showing their model.
• Very interesting! Surround might have a role in predicting what is going on at the center.

• Rahnev, D., Maniscalco, B., Graves, T., Huang, E., de Lange, F. P., & Lau, H. (2011). Attention induces conservative subjective biases in visual perception. Nature Neuroscience, 14(12)A
• Nice! Pretty neat results!
• Very interesting paper that show how attention (to a space) can reduce sensitivity and visibility.
• Authors argue that attending (to a pre-cued area) reduces inter-trial noise, therefore, leading to the signal not being able to hit the threshold. While sensitivity drops, observers had high confidence in their judgments

• Odegaard, B., Chang, M. Y., Lau, H., & Cheung, S.-H. (2018). Inflation versus filling-in: Why we feel we see more than we actually do in peripheral vision. Philosophical Transactions of the Royal Society B: Biological Sciences, A
• Why do we feel we think we see more than we actually do in peripheral vision?
• Nice overview about how visual experience in the periphery is sparse, while in fovea it is rich.
• This perceived richness for fovea might be spilling to the periphery, a false inference. Consistent to "self-consistent perception". People hold more liberal decision thresholds for the periphery (leading to more false alarms).
• But this might be adaptive as we can always saccade to the periphery (make periphery fovea).
• Grating orientation discrimination task in both single and crowded conditions.
• Result 1: people are better at orientation discrimination when they see a single grating vs multiple, and their metacognitive efficiency (a measure of how effectively confidence rating could distinguish between correct and incorrect judgments) reflect that.
• Result 2: People are better at foveal judgments (involving detection of congruently orientated lines), and metacognitive responses are inflated when for the ones that are on the periphery.
• "peripheral perception leads to both erroneous overconfidence and liberal detection bias, that led us to think these findings may be relevant for subjective phenomenology"
• Nice criticism: link btw confidence and perceptual experience is tenuous.

• Haxby, J. V., Gobbini, M. I., Furey, M. L., Ishai, A., Schouten, J. L., & Pietrini, P. (2001). Distributed and Overlapping Representations of Faces and Objects in Ventral Temporal Cortex. Science
• Neural activity for processing objects, places, faces is all distributed in different cortical regions.

• Cohen, M. A., Dennett, D. C., & Kanwisher, N. (2016). What is the Bandwidth of Perceptual Experience? Trends in Cognitive Sciences,A
• Authors argue (and present evidence) that we might be seeing less of what we think we are seeing (especially in the periphery). I like it.
• Examples of limits of perceptual experience and attention: inattentional blindness, change blindness.
• Authors argue that attending (to a pre-cued area) reduces inter-trial noise, therefore, leading to the signal not being able to hit the threshold. While sensitivity drops, observers had high confidence in their judgments