Spatial and sustained attention in relation to smoking status: behavioural performance and brain activation patterns

Abstract

Nicotine enhances attentional functions. Since chronic nicotine exposure through smoking induces neuroadaptive changes in the brain at a structural and molecular level, the present functional MRI (fMRI) study aimed at investigating the neural mechanisms underlying visuospatial and sustained attention in smokers and non-smokers. Visuospatial attention was assessed with a location-cueing paradigm, while sustained attention was measured by changes in response speed over time. During invalid trials, neural activity within the basal forebrain was selectively enhanced in smokers and higher basal forebrain activity was associated with increased parietal cortex activation. Moreover, higher levels of expired carbon monoxide in smokers before scanning were associated with higher parietal cortex activation and faster responses to invalidly cued targets. Smokers showed a slowing of responses and additionally recruited an area within the right supramarginal gyrus with increasing time on task. Activity decreases over time were observed in visual areas in smokers. The data provide evidence for altered attentional functions in smokers as compared with non-smokers, which were partly modulated by residual nicotine levels and were observed at a behavioural level for sustained and at a neural level for spatial and sustained attention.

Cholinergic modulation of the medial prefrontal cortex: the role of nicotinic receptors in attention and regulation of neuronal activity

“…Although nicotine seems to improve cognition in certain patient populations including schizophrenia, ADHD and dementias (Newhouse et al, 2004; Potter and Newhouse, 2008; D’Souza and Markou, 2012), the evidence for an attention enhancing effect in healthy populations is scarce (Newhouse et al, 2004; Heishman et al, 2010). Moreover, people that are addicted to smoking function better when they are not in a state of abstinence (Kleykamp et al, 2005; Vossel et al, 2011) although this seems to reduce a cognitive deficit associated with the abstinence rather than to really improve attention. Importantly, in humans it is unlikely that smokers represent an unbiased sample of the population.…”

The Yin and Yang of Nicotine: Harmful during Development, Beneficial in Adult Patient Populations

“…However, this beneficial effect of nicotine is in the context of generally impaired attention and cognitive ability after nicotine deprivation (Kleykamp et al, 2011; Vossel et al, 2011). In fact, the effect of nicotine, as that of many other drugs, resembles an inverted U-shape function in which subjects who perform at suboptimum levels will show increased performance after drug stimulation (Newhouse et al, 2011).…”

Frontoparietal attentional network activation differs between smokers and nonsmokers during affective cognition

“…However, very little work has reported on smoker-nonsmoker differences in neurocognition. In a recent study investigating the functional neuroanatomical correlates of attention, smokers relative to nonsmokers exhibited reduced attention-related neural activation in visual cortex and increased activation in parietal cortex that correlated with time on task (Vossel et al, 2011). Yet, smoker-nonsmoker differences in brain cue-reactivity to emotional stimuli and the effects of emotional cues on attention remain unclear.…”