Sexual cues alter working memory performance and brain processing in men with compulsive sexual behavior

Pornography has been repeatedly at the centre of public attention and has been controversially discussed for a long time. However, little is known about the connection between pornographic stimuli and individual (neuronal) processing of attention and memory. Here, the impact and neural underpinnings of pornographic pictures on working memory processes in a sample of subjects with compulsive sexual behaviour was investigated. Therefore, whilst using functional magnetic resonance imaging (fMRI), a letter n-back task with neutral or pornographic pictures in the background was employed in 38 patients and 31 healthy controls. On the behavioural level, patients were slowed down by pornographic material depending on their pornography consumption in the last week, which was reflected by a higher activation in the lingual gyrus. In addition, the lingual gyrus showed a higher functional connectivity to the insula during processing of pornographic stimuli in the patient group. In contrast, healthy subjects showed faster responses when confronted with pornographic pictures only with high cognitive load. Also, patients showed a better memory for pornographic pictures in a surprise recognition task compared to controls, speaking for a higher relevance of pornographic material in the patient group. These findings are in line with the incentive salience theory of addiction, especially the higher functional connectivity to the salience network with the insula as a key hub and the higher lingual activity during processing of pornographic pictures depending on recent pornography consumption.

Expectation influences the interruptive function of pain: Behavioural and neural findings

BACKGROUND

Expectations can dramatically influence the perception of pain, as has been shown in placebo analgesia or nocebo hyperalgesia. Here, we investigated the role of expectation on the interruptive function of pain - the negative consequences of pain on cognitive task performance - in 42 healthy human subjects.

METHODS

Verbal and written instructions were used to manipulate the subjects' expectation of how pain would influence their task performance in an established visual categorization task which was performed with or without concomitant painful thermal stimulation during 3T fMRI scanning. The categorization task was followed by a surprise recognition task.

RESULTS

We observed a significant interaction between stimulation (pain/no pain) and expectancy (positive expectation/negative expectation): categorization accuracy decreased during painful stimulation in the negative expectancy group (N = 21), while no difference was observed in the positive expectancy group (N = 21). On the neural level, the positive expectancy group showed stronger activity in the anterior cingulate cortex (ACC) and hippocampus during painful stimulation compared to the negative group. Moreover, we detected a decrease in connectivity between ACC and fusiform gyrus during painful stimulation in the negative expectancy group, which was absent in the positive expectancy group.

CONCLUSION

Taken together, our data show that expectation can modulate the effect of pain on task performance and that these expectancy effects on the interruptive function of pain are mediated by activity and connectivity changes in brain areas involved in pain processing and task performance. The possibility of changing cognitive task performance by verbal information in clinical population warrants further investigation.

SIGNIFICANCE

We show that the interruptive function of pain on concurrent visual task performance is influenced by expectation. Positive expectation can abolish the detrimental effects of pain on cognition. These expectancy effects on the interruptive function of pain are mediated by changes in functional connectivity between rostral ACC, posterior fusiform cortex and the hippocampus.

Inside a synesthete's head: a functional connectivity analysis with grapheme-color synesthetes

Grapheme-color synesthesia is a condition in which letters are perceived with an additional color dimension. To identify brain regions involved in this type of synesthesia and to analyze functional connectivity of these areas, 18 grapheme-color synesthetes and 18 matched controls were stimulated with letters and pseudo-letters presented in black and color in an event-related fMRI experiment. Based on the activation-differences between synesthetes and non-synesthetic controls regions of interest were defined. In a second analysis step functional connectivity was calculated using beta series correlation analysis for these seed regions. First we identified one seed region in the left inferior parietal (IPL) cortex (BA7) showing activation differences between grapheme-color synesthetes and controls. Furthermore, we found activation differences in brain areas involved in processing of letters and pseudo-letters, in particular the right IPL cortex (BA7), but also two more clusters in the right hemispheric BA 18 and BA 40. Functional connectivity analysis revealed an increased connectivity between the left IPL seed region and primary/secondary visual areas (BA 18) in synesthetes. Also the right BA 7 showed a stronger connectivity with primary/secondary visual areas (BA 18) in grapheme-color synesthetes. The results of this study support the idea that the parietal lobe plays an important role in synesthetic experience. The data suggest furthermore that the information flow in grapheme-color synesthetes was already modulated at the level of the primary visual cortex which is different than previously thought. Therefore, the current models of grapheme-color synesthesia have to be refined as the unusual communication flow in synesthetes is not restricted to V4, fusiform cortex and the parietal lobe but rather involves a more extended network.

The neural correlates of coloured music: a functional MRI investigation of auditory-visual synaesthesia

In auditory-visual synaesthesia, all kinds of sound can induce additional visual experiences. To identify the brain regions mainly involved in this form of synaesthesia, functional magnetic resonance imaging (fMRI) has been used during non-linguistic sound perception (chords and pure tones) in synaesthetes and non-synaesthetes. Synaesthetes showed increased activation in the left inferior parietal cortex (IPC), an area involved in multimodal integration, feature binding and attention guidance. No significant group-differences could be detected in area V4, which is known to be related to colour vision and form processing. The results support the idea of the parietal cortex acting as sensory nexus area in auditory-visual synaesthesia, and as a common neural correlate for different types of synaesthesia.