Temporal Lobe Cortical Electrical Stimulation during the Encoding and Retrieval Phase Reduces False Memories

A recent study found that false memories were reduced by 36% when low frequency repetitive transcranial magnetic stimulation (rTMS) was applied to the left anterior temporal lobe after the encoding (study) phase. Here we were interested in the consequences on a false memory task of brain stimulation throughout the encoding and retrieval task phases. We used transcranial direct current stimulation (tDCS) because it has been shown to be a useful tool to enhance cognition. Specifically, we examined whether tDCS can induce changes in a task assessing false memories. Based on our preliminary results, three conditions of stimulation were chosen: anodal left/cathodal right anterior temporal lobe (ATL) stimulation (“bilateral stimulation”); anodal left ATL stimulation (with a large contralateral cathodal electrode – referred as “unilateral stimulation”) and sham stimulation. Our results showed that false memories were reduced significantly after the two active conditions (unilateral and bilateral stimulation) as compared with sham stimulation. There were no significant changes in veridical memories. Our findings show that false memories are reduced by 73% when anodal tDCS is applied to the anterior temporal lobes throughout the encoding and retrieval stages, suggesting a possible strategy for improving certain aspects of learning

Cannabis sativa and the endogenous cannabinoid system: therapeutic potential for appetite regulation

The herb Cannabis sativa (C. sativa) has been used in China and on the Indian subcontinent for thousands of years as a medicine. However, since it was brought to the UK and then the rest of the western world in the late 19th century, its use has been a source of controversy. Indeed, its psychotropic side effects are well reported but only relatively recently has scientific endeavour begun to find valuable uses for either the whole plant or its individual components. Here, we discuss evidence describing the endocannabinoid system, its endogenous and exogenous ligands and their varied effects on feeding cycles and meal patterns. Furthermore we also critically consider the mounting evidence which suggests non‐tetrahydrocannabinol phytocannabinoids play a vital role in C. sativa‐induced feeding pattern changes. Indeed, given the wide range of phytocannabinoids present in C. sativa and their equally wide range of intra‐, inter‐ and extra‐cellular mechanisms of action, we demonstrate that non‐Δ9tetrahydrocannabinol phytocannabinoids retain an important and, as yet, untapped clinical potential

Cannabinoid activity curtails cocaine craving

Behavioral studies demonstrate that the central mechanism involved in cocaine relapse is closely linked to the sites where marijuana has its effect, suggesting that cannabinoid receptor antagonists may be used as anti-craving agents

Manipulation of Pre-Target Activity on the Right Frontal Eye Field Enhances Conscious Visual Perception in Humans

The right Frontal Eye Field (FEF) is a region of the human brain, which has been consistently involved in visuo-spatial attention and access to consciousness. Nonetheless, the extent of this cortical site’s ability to influence specific aspects of visual performance remains debated. We hereby manipulated pre-target activity on the right FEF and explored its influence on the detection and categorization of low-contrast near-threshold visual stimuli. Our data show that pre-target frontal neurostimulation has the potential when used alone to induce enhancements of conscious visual detection. More interestingly, when FEF stimulation was combined with visuo-spatial cues, improvements remained present only for trials in which the cue correctly predicted the location of the subsequent target. Our data provide evidence for the causal role of the right FEF pre-target activity in the modulation of human conscious vision and reveal the dependence of such neurostimulatory effects on the state of activity set up by cue validity in the dorsal attentional orienting network

The Role of Intuition in the Generation and Evaluation Stages of Creativity

Both intuition and creativity are associated with knowledge creation, yet a clear link between them has not been adequately established. First, the available empirical evidence for an underlying relationship between intuition and creativity is sparse in nature. Further, this evidence is arguable as the concepts are diversely operationalized and the measures adopted are often not validated sufficiently. Combined, these issues make the findings from various studies examining the link between intuition and creativity difficult to replicate. Nevertheless, the role of intuition in creativity should not be neglected as it is often reported to be a core component of the idea generation process, which in conjunction with idea evaluation are crucial phases of creative cognition. We review the prior research findings in respect of idea generation and idea evaluation from the view that intuition can be construed as the gradual accumulation of cues to coherence. Thus, we summarize the literature on what role intuitive processes play in the main stages of the creative problem-solving process and outline a conceptual framework of the interaction between intuition and creativity. Finally, we discuss the main challenges of measuring intuition as well as possible directions for future research

The roles of left versus right anterior temporal lobes in semantic memory:A neuropsychological comparison of post-surgical temporal lobe epilepsy patients

The presence and degree of specialisation between the ATLs is a key issue indebates about the neural architecture of semantic memory. Here, we comprehensively assessed multiple aspects of semantic cognition in a large group of post-surgical TLE patients with left versus right anterior temporal lobectomy (n=41). Both subgroups showed deficits in expressive and receptive verbal semantic tasks, word and object recognition, naming and recognition of famous faces and perception of faces and emotions. Graded differences in performance between the left and right groups were secondary to the overallmild semantic impairment; primarily, left resected TLE patients showed weaker performance on tasks that required naming or accessing semantic information from a written word. Right resected TLE patients were relatively more impaired at recognising famous faces as familiar, although this effect was observed less consistently. These findings unify previous partial, inconsistent results and also align directly with fMRI and transcranial magnetic stimulation results in neurologically intact participants. Taken together, these data support a model inwhich the two ATLs act as a coupled bilateral system for the representation of semantic knowledge, and in which graded hemispheric specialisations emerge as a consequence of differential connectivity to lateralised speech production and face perception regions

Low-frequency repetitive transcranial magnetic stimulation of the anterior temporal lobes does not dissociate social versus nonsocial semantic knowledge

Social conceptual knowledge is imperative to communicate with, interact with, and interpret human society; however, little is known about the neural basis of social concepts. Previous research has predominantly suggested that the right anterior temporal lobe (ATL) may specifically represent social conceptual knowledge, whereas the left ATL is necessary for general semantic processing. However, this view has not always been supported by empirical studies. Employing a lateralized design and two different semantic tasks and a nonsemantic control task, we aimed to clarify some of these ambiguities by potentially dissociating left from right functionality and social from nonsocial concepts, using inhibitory repetitive transcranial magnetic stimulation (rTMS) coupled with a sham and control site stimulation ( N = 56). The results showed that stimulation of the left ATL led to overall faster processing times without affecting accuracy, whilst the right ATL and control groups did not significantly change in reaction times or accuracy. No difference occurred between social and nonsocial concepts after stimulation. This study is the first to show that inhibition of the left temporal lobe may improve performance on a semantic task and provides evidence that the ATLs may be lateralized in conceptual processing. The results do not confirm that the right temporal lobe is crucial for social conceptual processing, as inhibition did not significantly affect performance for social concepts. </jats:p