[Cognitive slowing in asymptomatic individuals who are seropositive for human immunodeficiency virus type 1].
BACKGROUND
Reaction time (RT) is thought to be the most suitable measure to detect cognitive deficits in neurologically asymptomatic human immunodeficiency virus type I (HIV-1) infected individual since cognitive slowing is the earliest signal of cognitive-motor disorder related to HIV-1 infection. There is evidence suggesting that the greater the degree of central processing demands required by a task, the more likely that it will be sensitive to the effect of HIV-1 infection. Such statement suggests that the RT deficits exhibited by HIV-1 infected individuals at initial stages could be caused by the slowing of central information processing mechanisms.


OBJECTIVE
To assess the relationships between demands of central information processing and RT in HIV-1 seropositive individuals.


METHODS
50 neurologically asymptomatic HIV-1 individuals were compared with 34 seronegative controls on four discriminative RT tasks of different levels of central processing demands except by the motor response requirements.


RESULTS
Seropositive group was slower in RT and performed worse on the higher demanding task. On the lesser demanding tasks no differences in RT nor in accuracy were observed. For the task demanding sensory coding efforts seropositive individual were slower but achieved the same level of accuracy.


CONCLUSIONS
Even when these results point to that RT slowing in HIV-1 asymptomatic individuals emerged with the increase in cognitive demands, the fact that RT slowing without accuracy declining can also appear in some tasks demanding sensory processing, preclude ruling out a peripheral deficit as the locus of the RT slowing in these subjects.
Instituto Nacional de Salud de los Trabajadores, Arroyo Naranjo, Ciudad de la Habana, Cuba.
F
F
Amador
J
J
Mayor-Ríos
N
N
del Castillo-Martín
D003072:Cognition Disorders / Q000097:blood / Q000821:virology*; D006679:HIV Seropositivity; D015497:HIV-1 / Q000276:immunology; D006801:Humans; D008297:Male; D009422:Nervous System Diseases / Q000097:blood / Q000821:virology; D009483:Neuropsychological Tests; D011597:Psychomotor Performance; D011930:Reaction Time / Q000502:physiology*