ipsilesional

Conditions of visual verbal extinction: does the ipsilesional stimulus have to be identified?

Performance is generally preserved in the side ipsilateral to the lesion (ipsilesional).

Here the stimulus on the affected side seems to lose under conditions of attentional competition from stimuli in the ipsilesional field.

The patient shows an affinity to the ipsilesional side being unable to disengage attention from that side.

A defect of mental representations may lead the patients to transpose all the elements to the ipsilesional side in drawing tasks.

Extinguished tactile stimulus does not access consciousness but it may interfere with perception of the ipsilesional one.

Patients show a contralesional loss of space representation with a deviation of spatial reference to the ipsilesional side.

Some evidence for a slight increase in detection of eccentric stimuli in the ipsilesional visual field - i.e. slightly improved peripheral vision.

Further, reaches with the ipsilesional arm had longer RTs to the cylinder, indicating more pre-planning and less reliance on on-line feedback.

Patients show increased difference in reaction time (crossed-uncrossed difference) for processing in contralesional and ipsilesional visual hemispheres.

The directional hypokinesia refers to a deficit of startup of the movements with the limb ipsilesional contralesional space.

Patients with this disorder will direct attention and movements to the ipsilesional side and neglect stimuli in the contralestionl side despite having preserved visual fields.

Hemispatial neglect is very commonly contralateral to the damaged hemisphere, but instances of ipsilesional neglect (on the same side as the lesion) have been reported.

When presented with stimuli, eye saccades from fixation point are more common in extinction patients, are longer in duration, and show ipsilesional bias in movement.

Patients with extinction do not report stimuli located in space contralateral to their damaged hemisphere when the stimuli are presented simultaneously with ipsilesional stimuli.

Faces in the contralesional field were less likely to be extinguished than other stimuli, but faces in the ipsilesional field appeared to induce more extinction events.

Patients with extinction will fail to perceive the stimulus in the contralesional visual field when presented in conjunction with a stimulus in the ipsilesional field.

Some forms of neglect may also be very mild-for example, in a condition called extinction where competition from the ipsilesional stimulus impedes perception of the contralesional stimulus.

Movement in the ipsilesional hand is segmented following unilateral brain damage Vaid, J., Singh, M., Sakhuja, T. et al.

If the examiner were to wiggle his or her fingers on both the affected and unaffected sides of the patient, the patient will report seeing movement only on the ipsilesional side.

In contrast, in neglect and extinction, patients may expect a stimulus to be presented on the affected side but still fail to report it when another, ipsilesional stimulus competes for attention.

Presenting a single word to a patient will result in the patient either reading only the ipsilesional part of the word or replacing the part they cannot see with a logical substitute.

Patients with tactile extinction are aware of being touched on a contralesional limb, but seem unaware of similar contralesional touch if touched simultaneously on their ipsilesional limb.

Milner and Goodale also suggest that visual extinction, the selective loss of awareness for contralesional stimuli that compete for selection with simultaneous ipsilesional events, reflects dorsal stream damage.

Visual extinction has the characteristic symptom of difficulty to perceive contralesional stimuli when presented simultaneously with an ipsilesional stimulus, but the ability to correctly identify them when not presented simultaneously.