Neurobehavioral Assessments of Cerebral Vasospasm - Animal Models of Acute Neurological Injuries: Injury and Mechanistic Assessments - page 563

damage can be assessed by measuring how much choice responses
deviate from those of control subjects and those predicted by
models of choice behavior that have been well validated by experi-
mental fi ndings.

To study potential damage to somatosensory cortex, tactile acuity
can be tested using the Go/No-Go and Forced-choice procedures
described for visual discrimination in Sect. 7.1, replacing the visual
stimuli with tactile ones, such as tactile vibrations of distinct fre-
quencies. When using Same/Different discrimination tasks, the
tactile stimuli are typically presented sequentially at the same physi-
cal location on the body, such as on a particular digit of one hand,
with the other hand free to respond. The sequential versions of the
tasks, therefore, test not only somatosensory perception, but work-
ing memory as well, since the latter is required to compare the fi rst
stimulus to the second. These tasks can also assess learning and
decision-making processes involved in somatosensory discrimina-
tion learning ( 215-217 ).

7.3. Somatosensory
Cortex

The most well-established functions of the temporal lobe are object
recognition, categorization, learning and memory, and auditory
processing. Match to sample (MTS) or delayed match to sample
(DMTS) are classic paradigms to test object discrimination, recog-
nition, and memory. In these tasks, a sample is fi rst presented,
which is followed by two options, one that matches the sample and
one that does not. The subject must of course select the matching
object (in nonmatch to sample, they must select the opposite).
Adding delays between the sample and test allows one to test object
memory. There are several variants of this paradigm allowing one
to test various related functions of temporal cortex. For example,
categorization ability can be assessed by requiring subjects to select
the test stimulus that is in the same category as the sample stimulus
(e.g., two different types of bird). If auditory stimuli are used, the
effects on auditory discrimination, categorization, etc. can be
assessed. More specifi c defi cits can also be assessed, such as whether
there are particular diffi culties with certain classes of stimuli such
as faces, the processing of which has been localized to the supe-
rior temporal gyrus as well as the temporal-parietal junction
( 218-220 ).
Object-based neglect has also been localized to dysfunction in
the superior temporal gyrus of the temporal lobe. A simple test to
assess this dysfunction is to require subjects to touch the left or
right side of objects displayed on a touch-sensitive screen.
Individuals with damage in the right hemisphere resulting in
object-based neglect, for example, tend to fail to touch the left side
of objects as opposed to the right side (independent of where the
object is displayed on the screen relative to fi xation).
Finally, multiple tests can be used to measure the effects on
learning due to temporal lobe damage. One well-known temporal

7.4. Temporal Cortex