scholarly journals Impaired performance in a conditioned reaction time task after thermocoagulatory lesions of the fronto-parietal cortex in rats

1998 ◽  
Vol 8 (4) ◽  
pp. 301-309 ◽  
Author(s):  
C Baunez
Keyword(s):  
Reaction Time ◽  
Parietal Cortex ◽  
Reaction Time Task ◽  
Conditioned Reaction ◽  
Impaired Performance ◽  
Time Task

scholarly journals Adaptive aspects of impulsivity and interactions with effects of catecholaminergic agents in the 5-choice serial reaction time task: implications for ADHD

2021 ◽  
Author(s):  
Chiara Toschi ◽  
Mona El-Sayed Hervig ◽  
Parisa Moazen ◽  
Maximilian G. Parker ◽  
Jeffrey W. Dalley ◽  
...  
Keyword(s):  
Reaction Time ◽  
Reaction Time Task ◽  
Serial Reaction Time Task ◽  
Superior Performance ◽  
Serial Reaction Time ◽  
Impaired Performance ◽  
Time Task ◽  
Serial Reaction ◽  
Behavioural Profile ◽  
Improved Performance

Abstract Background Work in humans has shown that impulsivity can be advantageous in certain settings. However, evidence for so-called functional impulsivity is lacking in experimental animals. Aims This study investigated the contexts in which high impulsive (HI) rats show an advantage in performance compared with mid- (MI) and low impulsive (LI) rats. We also assessed the effects of dopaminergic and noradrenergic agents to investigate underlying neurotransmitter mechanisms. Methods We tested rats on a variable inter-trial interval (ITI) version of the 5-choice serial reaction time task (5CSRTT). Rats received systemic injections of methylphenidate (MPH, 1 mg/kg and 3 mg/kg), atomoxetine (ATO, 0.3 mg/kg and 1 mg/kg), amphetamine (AMPH, 0.2 mg/kg), the alpha-2a adrenoceptor antagonist atipamezole (ATI, 0.3 mg/kg) and the alpha-1 adrenoceptor agonist phenylephrine (PHEN, 1 mg/kg) prior to behavioural testing. Results Unlike LI rats, HI rats exhibited superior performance, earning more reinforcers, on short ITI trials, when the task required rapid responding. MPH, AMPH and ATI improved performance on short ITI trials and increased impulsivity in long ITI trials, recapitulating the behavioural profile of HI. In contrast, ATO and PHEN impaired performance on short ITI trials and decreased impulsivity, thus mimicking the behavioural profile of LI rats. The effects of ATO were greater on MI rats and LI rats. Conclusions These findings indicate that impulsivity can be advantageous when rapid focusing and actions are required, an effect that may depend on increased dopamine neurotransmission. Conversely, activation of the noradrenergic system, with ATO and PHEN, led to a general inhibition of responding.

Covert orienting of attention in macaques. II. Contributions of parietal cortex

1995 ◽  
Vol 74 (2) ◽  
pp. 698-712 ◽  
Author(s):  
D. L. Robinson ◽  
E. M. Bowman ◽  
C. Kertzman
Keyword(s):  
Reaction Time ◽  
Receptive Field ◽  
Parietal Cortex ◽  
Visual Cues ◽  
Reaction Time Task ◽  
Visual Response ◽  
Attention Task ◽  
Time Task ◽  
Visual Spatial ◽  
Visual Targets

1. To understand some of the contributions of parietal cortex to the dynamics of visual spatial attention, we recorded from cortical cells of monkeys performing attentional tasks. We studied 484 neurons in the intraparietal sulcus and adjacent gyral tissue of two monkeys. We measured phasic responses to peripheral visual stimuli while the monkeys attended toward or away from the stimuli or when attention was not controlled. Neurons were tested while the monkeys gazed at a spot of light (simple fixation task), actively attended to a foveal target (foveal attention task), performed a reaction time task (cued reaction time task), made saccadic eye movements to visual targets (saccade task), or responded to a repetitious peripheral target (probability task). 2. In a previous paper we demonstrated that monkeys, like humans, responded more quickly to visual targets when the targets followed briefly flashed visual cues (validly cued targets) (Bowman et al. 1993). It has been hypothesized that the cue attracts attention to its locus and results in faster reaction times (Posner 1980). In the present physiological studies, visual cues consistently excited these neurons when they were flashed in the receptive field. Such activity might signal a shift of attention. Visual targets that fell within the receptive field and that immediately followed the cue evoked relatively weak responses. This response was due to a relative refractory period. 3. Next we tested attentional processes in these tasks that were independent of the visual response to the cue. We placed the cue outside of the receptive field and the target within the receptive field. We found that 23% of these cells had a significant decrease in their firing rate to validly cued targets in their receptive fields under these conditions. Strong responses were evoked by the same target when the cue was flashed in the opposite hemifield (invalidly cued targets). Thus this group of neurons responded best when attention was directed toward the opposite hemifield. 4. For another group of parietal cells (13%) there was an enhanced response to targets in the visual receptive field when the cue was in the same hemifield. For the remaining 64% of the cells there was no significant modulation in this task. 5. The cued reaction time task involved exogenous control of attention; the sensory cue gave spatial and temporal direction to attention. We used several other tasks to test for endogenous control of attention.(ABSTRACT TRUNCATED AT 400 WORDS)

Modeling Within-Person Variance in Reaction Time Data of Older Adults

GeroPsych ◽  
2011 ◽  
Vol 24 (4) ◽  
pp. 169-176 ◽  
Author(s):  
Philippe Rast ◽  
Daniel Zimprich
Keyword(s):  
Reaction Time ◽  
Cognitive Aging ◽  
Reaction Times ◽  
Reaction Time Task ◽  
Reaction Time Data ◽  
Scale Model ◽  
Time Data ◽  
Time Task ◽  
The Mean ◽  
Second Wave

In order to model within-person (WP) variance in a reaction time task, we applied a mixed location scale model using 335 participants from the second wave of the Zurich Longitudinal Study on Cognitive Aging. The age of the respondents and the performance in another reaction time task were used to explain individual differences in the WP variance. To account for larger variances due to slower reaction times, we also used the average of the predicted individual reaction time (RT) as a predictor for the WP variability. Here, the WP variability was a function of the mean. At the same time, older participants were more variable and those with better performance in another RT task were more consistent in their responses.

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