Memory

INFERIOR TEMPORAL LOBE
Inferior temporal lobe neurons are directly connected with the entorhinal cortex -the "gateway to the hippocampus"- as well as to the amygdala. -Involved in the maintenance of short term emotional, visual and cognitive memory, and many display heightened activity during delay periods while learning -Concerned with the behavioral context in which learning occurs

Neurons in the inferior temporal gyrus convey information concerning current versus previous stimulus patterns and their behavioral context. IT neurons are therefore involved in remembering this information, matching it with previously learned information, and are capable of simultaneously transmitting these impressions (including contextual details) to other brain areas.

Hence, IT neurons are involved in both encoding, storage, and recall and interact with the amygdala and hippocampus in regard to learning, memory and recognition. It is in this manner and through these interconnects that IT neurons are involved in emotional as well as non-emotional cognitive processing and memory storage. Conversely, with injuries to the inferior temporal lobe, visual and verbal memory functions suffer.

MEMORY, THE HIPPOCAMPUS & INFERIOR MEDIAL TEMPORAL LOBE
The entorhinal, perirhinal, and parahippocampal neocortex are located in the inferior and medial temporal lobe and are adjacent to and richly interconnected with the hippocampus which is buried within its depths.The inferior and medial temporal lobes are involved in memory functioning and may in fact serve as neuronal memory depots that becomes activated during recognition. "Middle temporal firing patterns may contribute to the reactivation of neocortical circuits encoding a particular stimulus-context gestalt" which in turn makes recognition and retrieval possible.

Inferior and medial temporal lobe -Exceedingly vivid personal memories may be triggered and recalled -May report seeing a complex scene from their past or early childhood, including hearing conversations, seeing faces, experiencing somesthetic sensations, and related events. These scenes do not move forward in time and are otherwise quite static, like a wide angle, multi-sensory snapshot.
 * Electrical Stimulation**

The entorhinal cortex and hippocampus appear to be the crucial structures, whereas the neocortex may be the site where memories are stored. In that the inferior and inferior medial temporal lobes also contain neurons which are selectively sensitive to particular sensory features, and will fire in response to faces, hands, and geometric patterns and objects, it is possible that not only are auditory and visual memories stored within the inferior temporal lobe, but that it may act as an associational warehouse (so to speak) from which particular auditory-visual images can be activated, retrieved and so that comparisons can be made. Through the neocortex the hippocampus and amygdala can gain access to particular perceptual images as well as store associated information via the aid and guidance of the neural circuits maintained in the entorhinal cortex and through which information is transmitted to both nuclei.

-Aacts as a gateway via which information from the immediately adjacent perirhinal cortex (which sits above and is richly interconnected with the amygdala) and the parahippocampal gyrus (which receives visual, auditory and tactual neocortical information) is analyzed and is then transmitted into the hippocampus. It is also via the entorhinal area that the hippocampus receives amygdaloid projections and fibers from the orbital frontal and temporal lobes. These neocortical regions are thus highly important in memory.
 * entorhinal cortex**

TEMPORAL LOBE INJURIES & MEMORY LOSS
It has long been known that damage to the temporal lobes can produce profound disturbances in the learning and recollection of verbal and visual stimuli. For example, left temporal lobectomy, siezures or lesions involving the inferior temporal areas can moderately disrupt immediate and severely impair delayed memory for verbal passages, and the recall of verbal paried-associates, consonant trigrams, word lists and number sequences. Similarly, severe anterograde and retrograde memory loss for verbal material has been noted when the anterior and posterior temporal regions (respectively) are electrically stimulated. In contrast, right temporal lesions or lobectomy significantly impair recognition memory for tactile and recurring visual stimuli such as faces and meaningless designs, as well as memory for object position and orientation, and visual-pictorial stimuli. Electrical stimulation of the right anterior and posterior temporal region also causes respectively, severe anterograde and retrograde memory loss for designs and geometric stimuli, and impairs memory for faces. With bilateral removal of the inferior temporal region there results a condition which has been variably referred to as "psychic blindness" and the "Kluver-Bucy syndrome". However, as explained in chapter 13, this is due to destruction of the amygdala. If the mesial regions are removed, severe memory disturbances involving visual and auditory stimuli result such that the patient suffers a permanent anterograde amnesia, including facial processing impairments. Anterior temporal region - more involved in initial consolidation storage phase of memory Posterior temporal region - more involved in memory retrieval and recall. Temporal lobes directly interact with the frontal lobes in memorization and remembering. The greater the activation of the frontal and temporal lobes (and associated tissues), the greater is the likelihood that subjects will remember whereas reduced activity is associated with forgetting. Hence, these areas interact to promote memory and retention. In consequence, if the frontal lobe is injured, and even if the temporal lobes are spared, patients may demonstrate significant memory loss --due to an inability to correctly search for and find the memory.

Bilateral destruction of the anterior hippocampus results in striking and profound disturbances involving memory and new learning (i.e. anterograde amnesia).

Presumably the hippocampus acts to protect memory and the encoding of new information during the storage and consolidation phase via the gating of afferent streams of information and the filtering/exclusion (or dampening) of irrelevant and interfering stimuli. When the hippocampus is damaged there results input overload, the neuroaxis is overwhelmed by neural noise, and the consolidation phase of memory is disrupted such that relevant information is not properly stored or even attented to. Consequently, the ability to form associations (e.g. between stimulus and response) or to alter preexisting schemas (such as occurs during learning) is attenuated.