scholarly journals Double dissociation in radial and rotational motion sensitivity

PLoS ONE ◽  
2021 ◽  
Vol 16 (1) ◽  
pp. e0246094
Author(s):  
Nestor Matthews ◽  
Leslie Welch ◽  
Elena K. Festa ◽  
Anthony A. Bruno
Keyword(s):  
College Students ◽  
Phase Noise ◽  
Rotational Motion ◽  
Temporal Order ◽  
Temporal Order Judgment ◽  
Positional Information ◽  
Neural Mechanisms ◽  
Motion Sensitivity ◽  
Double Dissociation ◽  
Double Dissociations

Neurophysiological experiments have shown that a shared region of the primate visual system registers both radial and rotational motion. Radial and rotational motion also share computational features. Despite these neural and computational similarities, prior experiments have disrupted radial, but not rotational, motion sensitivity -a single dissociation. Here we report stimulus manipulations that extend the single dissociation to a double dissociation, thereby showing further separability between radial and rotational motion sensitivity. In Exp 1 bilateral plaid stimuli with or without phase-noise either radiated or rotated before changing direction. College students reported whether the direction changed first on the left or right–a temporal order judgment (TOJ). Phase noise generated significantly larger disruptions to rotational TOJs than to radial TOJs, thereby completing the double dissociation. In Exp 2 we conceptually replicated this double dissociation by switching the task from TOJs to simultaneity judgments (SJs). Phase noise generated significantly larger disruptions to rotational SJs than to radial SJs. This disruption pattern reversed after changing the plaids’ motion from same- to opposite-initial directions. The double dissociations reported here revealed distinct dependencies for radial and rotational motion sensitivity. Radial motion sensitivity depended strongly on information about global depth. Rotational motion sensitivity depended strongly on positional information about local luminance gradients. These distinct dependencies arose downstream from the neural mechanisms that detect local linear components within radial and rotational motion. Overall, the differential impairments generated by our psychophysical experiments demonstrate independence between radial and rotational motion sensitivity, despite their neural and computational similarities.

scholarly journals Double Dissociation in Radial & Rotational Motion-Defined Temporal Order Judgments

2018 ◽  
Vol 18 (10) ◽  
pp. 330
Author(s):  
Leslie Welch ◽  
Nestor Matthews ◽  
Elena Festa ◽  
Kendra Schafer
Keyword(s):  
Rotational Motion ◽  
Temporal Order ◽  
Double Dissociation ◽  
Temporal Order Judgments

scholarly journals The time course of synaesthetic colour perception

2020 ◽  
Author(s):  
Laura Lungu ◽  
Nicolas Rothen ◽  
Devin Terhune
Keyword(s):  
Time Course ◽  
Temporal Order ◽  
Temporal Order Judgment ◽  
Neural Mechanisms ◽  
Top Down ◽  
Colour Perception ◽  
Bottom Up

Grapheme-colour synaesthesia is a neurodevelopmental condition wherein perception of numbers and letters consistently and involuntarily elicits the concurrent experience of a colour photism. Accumulating evidence suggests that heterogeneity in the visuospatial phenomenology of synaesthesia is attributable to the operation of top-down processes underlying photisms experienced as representations in associator synaesthetes and bottom-up processes subserving photisms experienced as spatially localized in projector synaesthetes. An untested corollary of this hypothesis is that bottom-up mechanisms will actuate earlier photism perception in projector synaesthetes. We tested this prediction in a pre-registered study in which associators and projectors completed adaptive temporal order judgment tasks for graphemes, colours, and photisms. In corroboration of the hypothesis of differential photism access across visuospatial phenomenology subtypes, projectors displayed earlier photism colour thresholds than associators whereas the two subtypes did not significantly differ in veridical colour thresholds. Synesthetes did not differ in grapheme or colour thresholds relative to non-synesthete controls, contrary to previous suggestions of superior colour processing in this condition. These results are consistent with the proposal of differential neural mechanisms underlying photism perception in subtypes of grapheme-colour synaesthesia and warrant renewed attention to heterogeneity in the mechanisms and phenomenology of this condition.

Time changes: Temporal contexts support event segmentation in associative memory

2020 ◽  
Author(s):  
Vincent van de Ven ◽  
Moritz Jaeckels ◽  
Peter De Weerd
Keyword(s):  
Associative Memory ◽  
Temporal Order ◽  
Temporal Order Judgment ◽  
Temporal Context ◽  
Temporal Acuity ◽  
Event Segmentation ◽  
Standard Interval ◽  
Test Items ◽  
Time Changes ◽  
Temporal Order Judgments

We tend to mentally segment a series of events according to perceptual contextual changes, such that items from a shared context are more strongly associated in memory than items from different contexts. It is also known that temporal context provides a scaffold to structure experiences in memory, but its role in event segmentation has not been investigated. We adapted a previous paradigm, which was used to investigate event segmentation using visual contexts, to study the effects of changes in temporal contexts on event segmentation in associative memory. We presented lists of items in which the inter-stimulus intervals (ISIs) ranged across lists between 0.5 and 4 s in 0.5 s steps. After each set of six lists, participants judged which one of two test items were shown first (temporal order judgment) for items that were either drawn from the same list or from consecutive lists. Further, participants judged from memory whether the ISI associated to an item lasted longer than a standard interval (2.25s) that was not previously shown. Results showed faster responses for temporal order judgments when items were drawn from the same context, as opposed to items drawn from different contexts. Further, we found that participants were well able to provide temporal duration judgments based on recalled durations. Finally, we found temporal acuity, as estimated by psychometric curve fitting parameters of the recalled durations, correlated inversely with within-list temporal order judgments. These findings show that changes in temporal context support event segmentation in associative memory.

scholarly journals Temporal order judgment and simple reaction times: Evidence for a common processing system

2007 ◽  
Vol 7 (6) ◽  
pp. 11 ◽  
Author(s):  
Pedro Cardoso-Leite ◽  
Andrei Gorea ◽  
Pascal Mamassian
Keyword(s):  
Temporal Order ◽  
Temporal Order Judgment ◽  
Reaction Times ◽  
Processing System ◽  
Simple Reaction

Visual Simultaneity Judgments Activate a Bilateral Frontoparietal Timing System

2019 ◽  
Vol 31 (3) ◽  
pp. 431-441 ◽  
Author(s):  
Taylor Hanayik ◽  
Grigori Yourganov ◽  
Roger Newman-Norlund ◽  
Makayla Gibson ◽  
Chris Rorden
Keyword(s):  
Temporal Processing ◽  
Temporal Order ◽  
Spatial Information ◽  
Right Hemisphere ◽  
Temporal Order Judgment ◽  
Inferior Frontal Gyrus ◽  
Stimulus Presentation ◽  
Cognitive Networks ◽  
Temporal Perception ◽  
Sequence Of Events

In everyday life, we often make judgments regarding the sequence of events, for example, deciding whether a baseball runner's foot hit the plate before or after the ball hit the glove. Numerous studies have examined the functional correlates of temporal processing using variations of the temporal order judgment and simultaneity judgment (SJ) tasks. To perform temporal order judgment tasks, observers must bind temporal information with identity and/or spatial information relevant to the task itself. SJs, on the other hand, require observers to detect stimulus asynchrony but not the order of stimulus presentation and represent a purer measure of temporal processing. Some previous studies suggest that these temporal decisions rely primarily on right-hemisphere parietal structures, whereas others provide evidence that temporal perception depends on bilateral TPJ or inferior frontal regions (inferior frontal gyrus). Here, we report brain activity elicited by a visual SJ task. Our methods are unique given our use of two orthogonal control conditions, discrimination of spatial orientation and color, which were used to control for brain activation associated with the classic dorsal (“where/how”) and ventral (“what”) visual pathways. Our neuroimaging experiment shows that performing the SJ task selectively activated a bilateral network in the parietal (TPJ) and frontal (inferior frontal gyrus) cortices. We argue that SJ tasks are a purer measure of temporal perception because they do not require observers to process either identity or spatial information, both of which may activate separate cognitive networks.

scholarly journals Representation of Grammatical Categories of Words in the Brain

1995 ◽  
Vol 7 (3) ◽  
pp. 396-407 ◽  
Author(s):  
Argye E. Hillis ◽  
Alfonso Caramazza
Keyword(s):  
Neural Mechanisms ◽  
Single Patient ◽  
Grammatical Category ◽  
Lexical Knowledge ◽  
Double Dissociation ◽  
Category Information ◽  
Orthographic Representations ◽  
Organizational Principle ◽  
The Brain ◽  
Verbal Output

We report the performance of a patient who, as a consequence of left frontal and temporoparietal strokes, makes far more errors on nouns than on verbs in spoken output tasks, but makes far more errors on verbs than on nouns in written input tasks. This double dissociation within a single patient with respect to grammatical category provides evidence for the hypothesis that phonological and orthographic representations of nouns and verbs are processed by independent neural mechanisms. Furthermore, the opposite dissociation in the verbal output modality, an advantage for nouns over verbs in spoken tasks, by a different patient using the same stimuli has also been reported (Caramazza & Hillis, 1991). This double dissociation across patients on the same task indicates that results cannot be ascribed to "greater difficulty" with one type of stimulus, and provides further evidence for the view that grammatical category information is an important organizational principle of lexical knowledge in the brain.

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