scholarly journals Neuronal correlates of signal detection in the posterior parietal cortex of rats performing a sustained attention task

Neuroscience ◽  
2006 ◽  
Vol 143 (2) ◽  
pp. 407-417 ◽  
Author(s):  
J. Broussard ◽  
M. Sarter ◽  
B. Givens
2019 ◽  
Vol 25 (09) ◽  
pp. 972-984
Author(s):  
Tian Gan ◽  
Stevan Nikolin ◽  
Colleen K. Loo ◽  
Donel M. Martin

AbstractObjectives:Noninvasive brain stimulation methods, including high-definition transcranial direct current stimulation (HD-tDCS) and theta burst stimulation (TBS) have emerged as novel tools to modulate and explore brain function. However, the relative efficacy of these newer stimulation approaches for modulating cognitive functioning remains unclear. This study investigated the cognitive effects of HD-tDCS, intermittent TBS (iTBS) and prolonged continuous TBS (ProcTBS) and explored the potential of these approaches for modulating hypothesized functions of the left posterior parietal cortex (PPC).Methods:Twenty-two healthy volunteers attended four experimental sessions in a cross-over experimental design. In each session, participants either received HD-tDCS, iTBS, ProcTBS or sham, and completed cognitive tasks, including a divided attention task, a working memory maintenance task and an attention task (emotional Stroop test).Results:The results showed that compared to sham, HD-tDCS, iTBS and ProcTBS caused significantly faster response times on the emotional Stroop task. The effect size (Cohen’sd) wasd= .32 for iTBS (p< .001), .21 for ProcTBS (p= .01) and .15 for HD-tDCS (p= .044). However, for the performance on the divided attention and working memory maintenance tasks, no significant effect of stimulation was found.Conclusions:The results suggest that repetitive transcranial magnetic stimulation techniques, including TBS, may have greater efficacy for modulating cognition compared with HD-tDCS, and extend existing knowledge about specific functions of the left PPC.


2020 ◽  
Author(s):  
Jochem van Kempen ◽  
Christian Brandt ◽  
Claudia Distler ◽  
Mark A. Bellgrove ◽  
Alexander Thiele

AbstractSelective attention facilitates the prioritization of task-relevant sensory inputs over those which are irrelevant. Although cognitive neuroscience has made great strides in understanding the neural substrates of attention, our understanding of its neuropharmacology is incomplete. Cholinergic and glutamatergic contributions have been demonstrated, but emerging evidence also suggests an important influence of dopamine (DA). DA has historically been investigated in the context of frontal/prefrontal function arguing that dopaminergic receptor density in the posterior/parietal cortex is sparse. However, this notion was derived from rodent data, whereas in primates DA innervation in parietal cortex matches that of many prefrontal areas. We recorded single- and multi-unit activity whilst iontophoretically administering dopaminergic agonists and antagonists to posterior parietal cortex of rhesus macaques engaged in a spatial attention task. Out of 88 neurons, 50 showed modulation of activity induced by drug administration. Dopamine inhibited firing rates across the population according to an inverted-U shaped dose-response curve. D1 receptor antagonists diminished firing rates in broad-spiking units according to a monotonically increasing function. Additionally, dopamine modulated attentional signals in broad, but not narrow-spiking cells. Finally, both drugs modulated the pupil light reflex. These data show that dopamine plays an important role in shaping neuronal responses and modulates attentional processing in macaque parietal cortex.Significance statementDopamine is critically involved in high-level cognitive functions, and dopaminergic dysfunctions pertain to ageing and neurological and psychiatric disorders. Most previous studies focused on dopaminergic effects on prefrontal activity or its role in basal ganglia circuitry. The effects of dopamine in other brain areas such as parietal cortex, despite its well-established role in cognition and cognitive dysfunction, have largely been overlooked. This study is the first to show dopaminergic modulation of parietal activity in general, and specific to spatial attention in the non-human primate, revealing cell-type specific effects of dopamine on attentional modulation.


2009 ◽  
Author(s):  
Philip Tseng ◽  
Cassidy Sterling ◽  
Adam Cooper ◽  
Bruce Bridgeman ◽  
Neil G. Muggleton ◽  
...  

2018 ◽  
Author(s):  
Imogen M Kruse

The near-miss effect in gambling behaviour occurs when an outcome which is close to a win outcome invigorates gambling behaviour notwithstanding lack of associated reward. In this paper I postulate that the processing of concepts which are deemed controllable is rooted in neurological machinery located in the posterior parietal cortex specialised for the processing of objects which are immediately actionable or controllable because they are within reach. I theorise that the use of a common machinery facilitates spatial influence on the perception of concepts such that the win outcome which is 'almost complete' is perceived as being 'almost within reach'. The perceived realisability of the win increases subjective reward probability and the associated expected action value which impacts decision-making and behaviour. This novel hypothesis is the first to offer a neurological model which can comprehensively explain many empirical findings associated with the near-miss effect as well as other gambling phenomena such as the ‘illusion of control’. Furthermore, when extended to other compulsive behaviours such as drug addiction, the model can offer an explanation for continued drug-seeking following devaluation and for the increase in cravings in response to perceived opportunity to self-administer, neither of which can be explained by simple reinforcement models alone. This paper therefore provides an innovative and unifying perspective for the study and treatment of behavioural and substance addictions.


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