CPS BLT Talk-Melchi Michel/UT-Austin Psychology Dept. SEA 4.242 Monday December 1 2008 12:00 p.m.

Contact Name: 
Jenna Whitney
Date: 
Dec 1, 2008 12:00pm - 1:00pm

Type of Talk: CPS BLT Talk

Speaker/Affilia

tion: Melchi Michel/University of Texas at Austin Psychology Department
Date/Time: Monday December 1 2008 12:00 p.m.

Location: SEA
4.242

Host: Sara Dow

Talk Title: The Plasticity of Saccadi

c Strategies in Visual Search

Talk Abstract:
Can human observer

s adapt their saccadic strategies to a new
retinal sensitivity map? Pe

rformance for an observer in a visual
search task depends critically on
two factors: the observer''s
particular ‘sensitivity map’

(i.e. the pattern of%A0falloff in target
detectability with retinal ec

centricity) and the observer''s saccadic
strategy (i.e. how the obser

ver moves its eyes). Note that these
two factors are not independent;

the optimal choice of eye
movements depends on the observer’s sen

sitivity map. Studies
using either retinopathy patients or artificial s

cotomas in normal
observers have repeatedly demonstrated that changes i

n the
sensitivity map lead to degraded performance in visual search
tasks. It remains unclear however whether these reductions in
perfor

mance reflect suboptimal saccadic strategies or whether
they can be com

pletely accounted for by the reductions in
sensitivity. %A0Using a gaze

-contingent display and an ideal observer
model of visual search (Najem

nik & Geisler 2005) we investigated
how normal observers modified the

ir saccadic strategies following
two types of simulated manipulations o

f their retinal sensitivity maps.
We provide evidence that observers ap

propriately modified their
saccadic strategies under at least one of ou

r manipulations and we
discuss the characteristics and limits of this (

short-term) saccadic
plasticity.