I. The Mind and brain of Short-Term Memory
This article discussed about major psychological concepts associated with short term memory and the manner by which the impact brain mechanisms. There was the inquiry about the characteristics of the memory system that permits humans to complete specific tasks. In this article, the focus is on three contexts underlying short-term memory and these are inline according to the premise concerning a) the structure of short-term memory, b) the processes that operate on the accumulated information, and c) the mechanisms of short-term memory that accounts about the process of forgetting.
There are many scholars who pointed out that short-term memory is vastly dissimilar from long term memory, and this concept is assumed in the study of patients who suffered from brain injuries. In the study, it was found that those who were found to have damaged parietal and temporal lobe manifested short-term memory impairment, but remains to have an intact long-term memory. However, further studies showed that “the representational bases for perception, STM and LTm are identical” (Jonides et al, 2008 p. 201). It was found that the neural representations that are activated in the storage of initial information indicated a sustained stimulation even under the mechanisms involved in long term-memory. This is further validated by the findings that the process of STM retrieval is similar to that of the LTM, because both of these systems are facilitated by an identical cue-based mechanisms. Further, scholars confirmed the similarity of STM and LTM retention based on “the heavy overlap in the neural substrates” (Jonides et al, 2008 p. 205) for both memories.
There is also the debate on whether the reason for forgetting is associated with time-based decay or interference (Jonides et al, 2008). The decay theory posits that memory wanes, so that information eventually becomes unavailable with the passage of time. On the other hand, the interference theory suggests that “items in memory compete with the amount of interference determined by the similarity, number and strength of the competitors” (Jonides et al, 2008, p. 210). Accordingly, while this article was not able to provide a conclusive premise on the relationship between LTM and STM, it is worth knowing that even a limited short-term retention does not lead to major interference to the body’s normal functioning.
II. Experimental and Theoretical Approaches to Concious Processing
In this article, the discussion focused on the experimental research and theories initiated as a means to validate or reject the concepts that link the relationship between the consciousness and neural activities. First, there is a need to appreciate the difference between the conscious state and the conscious contents. While this article pointed out that the word ‘conscious’ is a vague term, the discussion generally refers to the conscious information processing. Consequently, the limited amount of information accessed is referred to as the conscious content.
The emphasis made in this article concerns the manner by which the external or internal information becomes accessible in consciousness processing. In a study using the Global Neuronal Workspace (GNW) model, the researchers proposed that ‘neuronal workspace’ that interconnects the various unconscious processors are formed by the subset of cortical pyramidal cells and the related thalamocortical loops (Dehaene et al, 2011). Under this proposal, it is assumed that the sustained activity of the GNW enables the encoding of conscious content, while the rest of remain inhibited. The Globl Neural Workspace neurons contain multiple reciprocal connections that are tasked to amplify and sustain an intended neural representation. Consequently, the GNW axons communicate with other processors throughout the brain, and this process “allows information to be more efficiently processed” (Dehaene, 2011, p. 210). The processing and sharing of information is permitted because it is not longer restricted within the non-conscious parameters, rather, they attained a considerable flexibility that is the characteristics of cortical processors. In addition to that, they can already be verbally transmitted because, among the cortical processors are those that are involved in message formulation.
The studies in this article were generally concentrated on the straightforward and uncomplicated inquiry concerning neuro-physiological mechanisms and its aspects that helps determine the difference between conscious access and the non-conscious handling of unlike information. The focus of this study of simpler neural activities mandates further investigations on the claims made in this article, especially those that concern the higher level of consciousness.
III. Working Memory: Theories, Models, and Controversies
The prefaratory chapter written by Baddeley discusses the roots and eventual development of a diversified approach of understanding working memory. The author attempted to show the difference between the general, yet more stable theoretical frameworks and that of the more specific models within this structure. This article presented the concept of short-term memory which Baddeley referred to as “the simple temporary storage of information, in contrast to WM, which implies a storage and manipulation” (Baddeley, 2012, p. 4). The authors study of short-term and long-term memory resulted to his conclusion about the existence of “two storage systems, a short-term phonological and a long-term semantically based system” (Baddeley, 2012, p. 4). The author further wrote about evidences indicating that STM and LTM separate storage, for example, he cited bout the amnesic patients who were able to demonstrate an intact STM but weakened LTM, while there are other patients who showed a totally different pattern. Other evidence cited by the Baddeley is testing both the STM and LTM with the use one memory tasks. An example of which is the recency effect; that is, there is an increased chance in recalling the last few words from a list during the immediate test but this is almost difficult after a few moments of delay.
The article discussed about the relationship of working memory (WM) and long-term memory. According to Baddeley (2012), WM is stimulated by LTM because the use of the former involves the stimulation of multiple brain areas that includes the LTM. Further, he pointed out that his views concerning working memory are attributed to his interest in the study of patients who suffered from neuropsychological deficits and those that demonstrate cognitive impairments. Based on Baddeley’s study, he concluded that the popularity of the working memory concept is founded on the neurobiological studies that speculates on the dependence of anatomical locations. Aside from the neurobiological approaches in studying memory, the author also discussed alternative approaches such as the specific theory on STM storage, theories of WM and Cowan’s Embedded Processes Theory. Baddeley focused his discussion on the different theories on the LTM, STM and WM and their possible application even in an uncontrolled setting. It is, however, hoped that further studies will be carried out about theoretical models about cognition and memory.
The neuropsychology of face perception:
Beyond simple dissociations and functional selectivity
This article discusses the result of examination of people who have brain lesions and their related characteristics and behaviors. This is in order for researchers to draw inferences concerning the different processes underlying the individual’s face perception abilities, and which part of the brain stimulates such perceptions. Advances in technology, such as functional neuroimaging techniques have been able to help in the research in cognitive neuroscience in terms of face processing. Specifically, the discussion is centered on the findings using transcanial magnetic stimulation and other methods on people who are suffering from brain damage. The authors hypothesized that “the face perception is underpinned by a neural system that is more interactive and flexible than is typically captured by existing models of face perception” (Atkinson and Adolphs, 2011, p. 1726).
The study demonstrated how face processing is dependent on distributed networks of cortical areas located in the temporal and frontal lobes that characteristically respond to face stimuli, albeit disproportionately. On the other hand, the higher level face perception, such as those that require the deciding on the identity, determining other people's emotion rely on the “intact face-processing network that includes OFA, whereas lower-level face categorization abilities, such as discriminating faces from objects can be achieved without OFA (Atkison and Adolphs, 2011, p. 1733). The authors have shown evidence that supports the concept that the neural substrates concerning face perception are attributed to the complex interplay of different mechanism such as retinal image, attention and direct eye gaze. Nevertheless, there is still a need to conduct further studies and examine the dynamics that has an impact on the complexities associated with vision and perception.
References
Atkinson, A., Adolphs, R., (2011). The neuropsychology of face perception: Beyond simple dissociations and functional selectivity. Philosophical Transactions of the Royal Society. (366): 1726-1738
Baddeley, A. (2012). Working memory. Annual Review of Psychology (63): pp. 1-29
Dehaene, S., Changeux, J. (2011). Experimental and theoretical approaches to conscious processing. Neuron Review (70): pp. 200-227
Jonides, J., Lewis, R., Nee, D., Lustig, C., Bernan, M., Moore, K (2008). The Mind and brain of short-term memory. Annual Review of Psychology. 59 (193): pp. 193-224
