Effects of biasing the location of stimulus presentation, and the muscarinic cholinergic receptor antagonist scopolamine, on performance of a 5-choice serial reaction time attention task in rats

Abstract

A major purpose of the present studies was to determine the effects of varying the relative frequency, or bias, of stimulus presentation at different locations in a five-choice serial reaction time attention task. Training sessions were conducted in which the stimulus duration was held constant at 2 s and, initially, stimuli were presented with equal probability above each of the levers. During testing sessions, however, stimulus duration was either 0.2 or 2 s, and the frequency of presentation was varied among no bias, a middle bias, a left bias or a right bias condition. The training conditions were then changed such that the frequency of presentation was always a left bias, and test sessions were again conducted with no, middle, left or right bias. In the presence of the 0.2-s, but not the 2.0-s, stimulus, the percentage of correct responding on each of the choice levers during test sessions varied directly with the bias conditions in that the percentage of correct responding was highest at the most frequently presented location and lowest at the least frequently presented location. In addition, scopolamine, but not metscopolamine, increased omissions while also increasing anticipatory responses in rats trained under left-bias conditions and tested under right-bias conditions. The present findings suggest that varying the frequency of stimulus location can provide additional measures of attention in the five-choice serial reaction time task.

Nicotine Increases Impulsivity and Decreases Willingness to Exert Cognitive Effort despite Improving Attention in “Slacker” Rats: Insights into Cholinergic Regulation of Cost/Benefit Decision Making

“…Similarly, scopolamine decreased workers’ choice of HR but had no significant effect on accuracy. This lack of effect on accuracy stands in contrast to some 5CSRTT literature [41] , [42] , and may be the result of additional training for the rCET animals and differences in dosing methodology [43] , [44] . Altogether, it appears that acetylcholine manipulations affect multiple subsystems, including those that underlie decision making, attention, and impulsivity.…”

Cholinergic modulation of visuospatial responding in central thalamus

“…Scopolamine has been found to block long‐latency, long‐lasting depolarizing responses of thalamocortical neurons evoked by electrical stimulation of mesopontine cholinergic nuclei (Curró Dossi et al ., 1991). Systemic administration of scopolamine has consistently been shown to increase omissions for five choice serial reaction time tasks (5‐CSRTT) at doses around 0.25 µmol/kg (Jones & Higgins, 1995; Mizra & Stolerman, 2000; Lindner et al ., 2006; Shannon & Eberle, 2006) and to increase RT for other measures of visuomotor responding (Davidson et al ., 1999; Phillips et al ., 2000). Several of these studies have shown no effect of comparable doses of methyl scopolamine, providing evidence for a central site of action.…”

Default Mode Network Activity and Connectivity in Psychopathology

“…The DMN was originally characterized with "blocked" designs where data from active and passive conditions were averaged over multiple relatively longer periods and where activation was statistically greater during rest than during task conditions (Mazoyer et al 2001, Shulman et al 1997. Subsequent meta-analyses of PET (Mazoyer et al 2001, Shulman et al 1997 and fMRI data (Shannon & Eberle 2006) confirmed that across many materials (e.g., verbal and nonverbal), multiple modalities (e.g., visual and auditory), and many tasks, there was greater activation in the four core DMN regions during rest than during task performance.…”