The effects of TMS over dorsolateral prefrontal cortex on trans-saccadic memory of multiple objects

Humans typically make several rapid eye movements (saccades) per second. It is thought that visual working memory can retain and spatially integrate three to four objects or features across each saccade but little is known about this neural mechanism. Previously we showed that transcranial magnetic stimulation (TMS) to the posterior parietal cortex and frontal eye fields degrade trans-saccadic memory of multiple object features (Prime, Vesia, & Crawford, 2008, Journal of Neuroscience, 28(27), 6938-6949; Prime, Vesia, & Crawford, 2010, Cerebral Cortex, 20(4), 759-772.). Here, we used a similar protocol to investigate whether dorsolateral prefrontal cortex (DLPFC), an area involved in spatial working memory, is also involved in trans-saccadic memory. Subjects were required to report changes in stimulus orientation with (saccade task) or without (fixation task) an eye movement in the intervening memory interval. We applied single-pulse TMS to left and right DLPFC during the memory delay, timed at three intervals to arrive approximately 100ms before, 100ms after, or at saccade onset. In the fixation task, left DLPFC TMS produced inconsistent results, whereas right DLPFC TMS disrupted performance at all three intervals (significantly for presaccadic TMS). In contrast, in the saccade task, TMS consistently facilitated performance (significantly for left DLPFC/perisaccadic TMS and right DLPFC/postsaccadic TMS) suggesting a dis-inhibition of trans-saccadic processing. These results are consistent with a neural circuit of trans-saccadic memory that overlaps and interacts with, but is partially separate from the circuit for visual working memory during sustained fixation.

Gray Bay PSG - R234

The South Carolina Department of Natural Resources provides maps to recreational and state shellfish grounds, available to the public for recreational harvesting or to commercial harvest. This map shows the location of Gray Bay PSG - R234 Recreational Shellfish Ground in Charleston County.

The picture of Dorian Gray: beleza, arte, representação

A escolha da obra The Picture of Dorian Gray para objecto de uma análise literária de pendor retórico-estilístico é, acima de tudo, fruto de um gosto muito pessoal. Partindo da leitura rigorosa da obra em questão, concentrámo-nos inicialmente no particular de forma a tentar chegar a características distintivas da produção literária de Wilde. Esta afigurou-se-nos como a melhor estratégia para atingir o objectivo que nos propúnhamos: reconhecer a existência de um padrão específico na escrita do autor e estabelecer a forma como esse padrão exemplifica uma determinada época literária. E assim foi possível descortinar que Oscar Wilde dá ao mundo um único romance onde são profundamente explorados os ideais da Arte recriada, da Beleza reabilitada e das suas Representações teatrais. The Picture of Dorian Gray abre vários precedentes literários, de entre os quais se destaca a coragem de assumir na forma os preceitos convencionados pelos estetas para a vida quotidiana. Os leitores conquistados por tais técnicas são recompensados com a sensação por vezes indefinível de terem apreciado o mais recôndito da alma humana.

Representation of motor habit in a sequence of repetitive reach and grasp movements performed by macaque monkeys: evidence for a contribution of the dorsolateral prefrontal cortex.

In the context of an autologous cell transplantation study, a unilateral biopsy of cortical tissue was surgically performed from the right dorsolateral prefrontal cortex (dlPFC) in two intact adult macaque monkeys (dlPFC lesioned group), together with the implantation of a chronic chamber providing access to the left motor cortex. Three other monkeys were subjected to the same chronic chamber implantation, but without dlPFC biopsy (control group). All monkeys were initially trained to perform sequential manual dexterity tasks, requiring precision grip. The motor performance and the prehension's sequence (temporal order to grasp pellets from different spatial locations) were analysed for each hand. Following the surgery, transient and moderate deficits of manual dexterity per se occurred in both groups, indicating that they were not due to the dlPFC lesion (most likely related to the recording chamber implantation and/or general anaesthesia/medication). In contrast, changes of motor habit were observed for the sequential order of grasping in the two monkeys with dlPFC lesion only. The changes were more prominent in the monkey subjected to the largest lesion, supporting the notion of a specific effect of the dlPFC lesion on the motor habit of the monkeys. These observations are reminiscent of previous studies using conditional tasks with delay that have proposed a specialization of the dlPFC for visuo-spatial working memory, except that this is in a different context of "free-will", non-conditional manual dexterity task, without a component of working memory.

Journal du Camp de Gray commandé par M. Le duc de Randan

Ancien possesseur : Argenson, Antoine-René de Voyer (1722-1787 ; marquis de Paulmy d')

[Journal du Camp de Gray commandé par M. Le duc de Randan]. Ordre du 26. au 27. aoust

Ancien possesseur : Argenson, Antoine-René de Voyer (1722-1787 ; marquis de Paulmy d')

[Journal du Camp de Gray commandé par M. Le duc de Randan]. Ordre du 2. au 3. 7.bre 1754

Ancien possesseur : Argenson, Antoine-René de Voyer (1722-1787 ; marquis de Paulmy d')

[Journal du Camp de Gray commandé par M. Le duc de Randan]. Ordre du 3. au 4. 7.bre 1754

Ancien possesseur : Argenson, Antoine-René de Voyer (1722-1787 ; marquis de Paulmy d')

[Journal du Camp de Gray commandé par M. Le duc de Randan]. Du 4. au 5.

Ancien possesseur : Argenson, Antoine-René de Voyer (1722-1787 ; marquis de Paulmy d')

[Journal du Camp de Gray commandé par M. Le duc de Randan]. Ordre du 5. au 6. 7.bre

Ancien possesseur : Argenson, Antoine-René de Voyer (1722-1787 ; marquis de Paulmy d')