Alan Yu of the University of Chicago will present a colloq uium.
Click to join the Zoom meeting. The passcode is 63541 0. (The meeting ID is 647 6334 5823.)
Individual differ ences in categorization gradience: evidence from eye movement and neurophys iological measurements
Categorization is an important and fu ndamental human cognitive ability which allows a perceiver to treat objects with different physical features as functionally equivalent. A classic dem onstration of this ability is the phenomenon of categorical perception\, wh ere a continuous sequence of equal physical changes in a stimulus can be pe rceived and grouped as two different categories of stimuli. Within the spee ch domain\, however\, recent studies documented extensive individual variat ions in speech categorization\, even among typically-developed individuals.
In this talk\, I report the results of two recent experiments. The f irst experiment investigated the relationship between categorization gradie nce and cue weighting across two sets of English contrasts\, showing that s econdary cue weighting\, derived from eye movements in an eye-tracking expe riment\, correlates with how gradiently the listeners categorize speech sou nds. Greater categorization gradience is associated with larger secondary c ue weights. The relationship between categorization gradience and secondary cue weighting is observed across different types of cues and contrasts\, s uggesting that categorization gradience and cue weighting may be consistent speech processing properties at the individual level\, even if the specifi c magnitudes might differ across contrasts. We also found evidence that ind ividuals who integrate secondary cues during processing utilize a buffer pr ocessing strategy\, suggesting that delayed reaction to an early-arriving c ue until all relevant cues are available may facilitate the integration of multiple cues in the signal.
The second study investigated the underl ying neuro-mechanisms behind individual variability in categorization gradi ence\, by examining the subcortical and cortical speech-evoked responses. S pecifically\, we found that individuals differ in how the subcortical and c ortical representations diverge from each other\; higher redundancy (i.e. h igher similarity between the two representations) in speech information rel ayed from subcortical to cortical level correlates with more gradient categ orization\, whereas more categorical categorization correlates with more in formation reduction and abstraction (i.e. decreased similarity between the two representations) along successive processing stages. These studies high light the importance of understanding individual variability in speech proc essing and what such variation might mean for speech learning in general. CATEGORIES:Featured Events LOCATION:Online GEO:49.260872;-123.113953 URL;VALUE=URI:https://linguistics.ubc.ca/events/event/alan-yu-colloquium/ END:VEVENT BEGIN:VTIMEZONE TZID:America/Vancouver BEGIN:DAYLIGHT TZOFFSETFROM:-0800 TZOFFSETTO:-0700 DTSTART:20200308T100000 TZNAME:PDT END:DAYLIGHT END:VTIMEZONE END:VCALENDAR