Unformatted text preview: for attention
! e.g.,- Cannot process information in area
! Selects what information should access the
limited processing resources
Behavioral consequences of attention
Selective attention and orienting
Attention and eye movements
Physiological effects of attention
How is attention directed?
Corbetta's DAN and VAN
What is neglect?
! Definition, anatomy, symptoms
! Neglect and attention
! Neglect and spatial functions
! Body schema and awareness
! 44 ial neglect rather than with brain damage per se. (Modiﬁed from Becker & Karnath, 2010). (c) Scan paths (=gaze [combined eye and head orie
ents with spatial neglect (upper panel) during active visual search (black lines) as well as at rest (gray lines) as compared with a group of 1
lect (lower panel). The neglect patients show a marked bias of their active and their passive behavior toward the ipsilesional, right side (Modi
hannsen, & Karnath, 2008). What is spatial neglect? re unaware of their shifted spatial egocenter and
efault position. Despite variations in performance
s, this spontaneous behavior appears remarkably
uggests that there is a unitary, homogenous core
deﬁne as “spatial neglect” (illustrated in Fig. 1).
inical observations are a consequence of this core
rient toward the right whenever addressed (even
the left), and ignore contralesionally located peoreover, when they actively search for targets they
r exploratory eye and hand movements toward
space (Behrmann, Watt, Black, & Barton, 1997;
, Valenstein, & Damasio, 1983; Karnath, 1994b).
are precisely documented by recordings of these
1c; Karnath & Perenin, 1998; Karnath, Niemeier,
8) and are reliably measured by popular clinical
ying or cancellation tasks (where individuals are
numerous targets in a cluttered array) (Rorden & et al., 2011). These cortical areas also are involved in the
left hemisphere when patients show spatial neglect afte
hemisphere stroke (Suchan & Karnath, 2011).
Findings from tract tracing, myelin staining, and dif
tensor imaging techniques suggest a dense perisylvian n
interconnecting these three cortical sites (Fig. 2; Karnath,
the inferior parietal lobule with the lateral prefrontal cort
subcomponents II/III of the superior longitudinal fascicul
II/III] and the superior occipitofrontal fascicle [SOF]), later
frontal cortex with superior/middle temporal cortex (via
fasciculus [AF] and extreme capsule/inferior occipitofronta
culus [EmC/IOF]), and superior temporal cortex with the
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This note was uploaded on 04/11/2012 for the course NEURO NROC64 taught by Professor Matthias during the Winter '12 term at University of Toronto.
- Winter '12