Showing posts with label Cognitive Psychology. Show all posts
Showing posts with label Cognitive Psychology. Show all posts

Friday, December 02, 2022

Rising road fatalities

The current rising fatalities in the U.S. are caused by what University of Utah cognitive neuroscientist David Strayer, PhD, calls the “four horsemen of death.” Together, they are speed, impairment, distraction, and fatigue, the human foibles behind more than 90% of vehicle crashes.




Saturday, April 02, 2016

The McGurk effect

A phenomenon that occurs when a speech sound does not match the shape of the lips producing it, as when the sound corresponding to the usual pronunciation of the word gay is dubbed on to a video image of a person uttering the word bay, causing the listener to hear a word intermediate between the two (day).

The effect shows that the visual channel conveys important information not just to deaf people but also to listeners with normal hearing. For those with minor hearing loss, speech reading can be a very valuable way to maximize the hearing they still do have. Also, this reveals more about why watching the mouth is so important in intense language learning.

The phenomenon is named after the Scottish psychologist Harry McGurk (1936-98) who co-authored the first article on it, entitled 'Hearing Lips and Seeing Voices' in the journal Nature in 1976.


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Tuesday, March 01, 2016

Learned Helplessness and Depression

One cognitive account of depression is the Learned Helplessness Theory (Seligman, 1975). It argues, that depression occurs when people expect that bad events will occur and that there is nothing they can do to prevent them, or cope with them.

Learned Helplessness Theory emerged through Martin Seligman's work with laboratory dogs. He designed an experiment which consisted of three individual dogs, all restrained by harnesses. Dog group (a) was the control group, receiving no electric shock. Dog groups (b) were paired up. One dog in a pair was administered with a mild electric shock and at any time the dog could cease the electric shock by stepping their paw upon a lever. Dog group (c) were too paired up, however one of the dogs was a wired up to a dog in group b and the shocks they received were in congruence with that of group (b). The idea of this was that the group (c) dog would receive a shock that was erratic in timing, unavoidable and inescapable. The tests resulted in groups (a) and (b) recovering quite promptly from the experience. As predicted however, group (c) dogs were left meek and subdued; portraying symptoms similar to those of clinical depression and thus conforming to Seligman’s predictions: that helplessness can be learned. 



Learned helplessness results from being trained to be locked into a system. It can involve a state of apathy or passive behaviour induced by negative conditioning. People may believe that their personal 'defects' will render them helpless to avoid negative events in the future, and their sense of hopelessness places them at significantly greater risk for depression.

Although Seligman theorized that learned helplessness and depression had similar origins, the theory was widely criticized and he has since revised his ideas in his 'Explanatory Style'. This proposes that depression is linked to how we attribute causalities of certain events in our life or traits of our existence (i.e. whether we attribute events to internal, stable or global aspects) (Yen, 1998). Therefore, it is interesting to ask whether learned helplessness is in fact a cause of depression or a correlated side effect of becoming depressed.
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"Life inflicts the same setbacks and tragedies on the optimist as on the pessimist, but the optimist weathers them better" ~ Martin Seligman

Monday, January 04, 2016

I'll see you when I get my new glasses...

Have a look.




 
The Explanation: 
 
Inattentional blindness, a phenomenon known as "the failure to notice an unexpected stimulus that is in one’s field of vision when other attention-demanding tasks are being performed." This phenomenon is classified as a psychological attentional error - and you'll be relieved to know -  not the result of visionary deficits. The main reason for this lack of attention is the overload of stimuli surrounding us; in order to be able to focus on the intended things, we learn to disregard many others and be unaware of the unattended stimuli. There have been a large number of experiments demonstrating that this phenomenon has a significant effect on people’s perception...and now this one with you.
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"What we see depends mainly on what we look for." ~ John Lubbock

Friday, October 02, 2015

The Default Network Mode; The Brain's Screensaver

The default mode network (DMN) is a network of brain components active when during daydreaming, self-generated thought, and when not attending to outside stimuli. Marcus Raichle, the discoverer of the DMN, has referred to it as "the orchestrator of the self". It is most active when the brain is at rest or involved in social communication.
 
The concept of brain resting-state network arose from observations made when comparing cerebral perfusion during cognitive processing to that measured during passive baseline conditions such as at rest, that is, when subjects lie in the dark and are instructed to think about nothing in particular (Mevel, 2011).

Raichle first used the term in 2001 to describe the nature of brain activity when it is not engaged in any specific, externally focused task. It's been considered quite an elaborate system, and while there are no definitive functions of the DMN as of yet, some proposed have included internal processes such as self-reflection to diffused passive attention. The DMN is generally inhibited in most cognitive tasks, however, tasks that involve episodic memory does not deactivate the DMN - suggesting a link.

The main hypotheses associated with the DMN and cognitive functions are, the Internal Mentation Hypothesis, and the Sentinel Hypothesis. The Internal Mentation hypothesis holds that DMN is important in introspection and internal attention. The Sentinel Hypothesis argues that the DMN supports a low level ''exploratory'' attention that surveys for unexpected stimuli.

Although some variation occurs, the default network mostly includes medial brain structures, i.e., the ventral medial prefrontal cortex, the posterior cingulate cortex, the inferior parietal lobe, the lateral temporal cortex, the dorsal medial prefrontal cortex, and the hippocampal formation. Probing the functional anatomy of the network in detail reveals that it is best understood as multiple interacting subsystems (Buckner, 2008).


The link between DMN and episodic memory is well established. It is now known that retrieval of episodic memories, whether internally or externally cued; relies on the DMN (Cabeza et al., 2011). Further, dysfunction of both grey matter of DMN nodes as well as white matter connections are implicated in Alzheimer's Disease, a disease with obvious prominent effects on episodic memory. People with early signs of Alzheimer's Disease have unusual resting state signatures, while in Autism; the resting-state networks can be 'hyperconnected'.

People who are depressed show an increase in DMN activity. This is likely to be precisely because what characterizes depression is a sense of constant rumination and negative self-referential mental activity – in neurological terms being stuck in the DMN. (Smith, 2015). Others researchers discovered findings that suggest increased default mode network activation during meditation (Xu et al., 2014), indicating that this activation is related to the relaxed focus of attention, which allows spontaneous thoughts, images, sensations, memories, and emotions to emerge and pass freely, accepting them as part of the meditation process (Xu et al., 2014). The DMN has also been linked with depression (Belleau et al., 2014), schizophrenia (Mingoia et al., 2012), and post traumatic stress disorder (Lanius et al., 2009).

While the functional significance of the DMN remains unknown, converging evidence suggests that the DMN might be critical for self-referential processing (e.g., introspection). Age differences in the ability to deactivate the DMN has been found between older and younger adults, which may reflect the cognitive change experienced in normal aging (Park et al, 2009). The mental activity of the DMN has still not been rigorously assessed to date. Despite the growing amount of knowledge regarding the DMN physiology and anatomy, the cognitive function of this network is still poorly understood (Mevel, 2011).
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''Whatever resting activity is doing, its existence proves one thing - the brain only rests when you're dead'' ~ Miall (2009)