Dinishak.com MindBlog

All things between psychology and technology

July 2nd, 2017

Open source article looking at the effects of being tethered to our smartphones on working memory and fluid intelligence. Pretty much, keep that smartphone physically away from yourself if you have to focus and solve problems.

October 31st, 2016

I’ll be in the department of criminology at Fresno State University next week going over some aspects of the neuropsychology of sex offense. The topic of sex offending is not simple; there are numerous factors that go into it but I’ve been curious about the assessment of the neuropsychological functioning of offenders in the forensic setting. My talk will be an overview of what I’ve found


August 19th, 2016

As I assess more patients over time, I’m always coming back to the importance of observations during evaluation. I think a recent report’s behavioral observation section was over one page. Reminds me of Sherlock Holmes:

Let him, on meeting a fellow-mortal, learn at a glance to distinguish the history of the man, and the trade or profession to which he belongs. Puerile as such an exercise may seem, it sharpens the faculties of observation, and teaches one where to look and what to look for. By a man’s finger nails, by his coat-sleeve, by his boot, by his trouser knees, by the callosities of his forefinger and thumb, by his expression, by his shirt cuffs—by each of these things a man’s calling is plainly revealed. That all united should fail to enlighten the competent enquirer in any case is almost inconceivable.

—From “The Book of Life,” an article by Sherlock Holmes quoted in A Study in Scarlet

March 6th, 2015

Damasio in Descartes’ error: Emotion, reason, and the human brain (1994), observes:

The standardized psychological and neuropsychological tests revealed a superior intellect. . . Elliot performed normally on memory tests employing interference procedures.. . . In short, perceptual ability, past memory, short‐term memory, new learning, language, and the ability to do arithmetic were intact. Attention, the ability to focus on a particular mental content to the exclusion of others, was also intact, and so was working memory. . . My prediction that Elliott would fail on tests known to detect frontal lobe dysfunction was not correct. . . . What was the chance he would fare well in the prime personality test, the Minnesota Multiphasic Personality Inventory, also known as the MMPI? As you may have guessed by now, Elliot was normal in that one too. . . After all these tests, Elliot emerged as a man with a normal intellect who was unable to decide properly, especially when the decision involved personal or social matters.

Could it be that reasoning and decision making in the personal and social domain were different from reasoning and thinking in domains concerning objects, space, numbers, and words? Might they depend on different neural systems and processes? I had to accept the fact that despite the major changes that had followed his brain damage, nothing much could be measured in the laboratory with the traditional neuropsychological instruments. Other patients had shown this sort of dissociation. (pages 41–43)

As neuropsychologists, we are asked to assess an individual’s ability to carry out complex everyday tasks including social interactions and juggling plans for the future. We try our best, in a limited amount of time, to capture executive functions with standardized measures in an artificial setting. It’s important to remember the importance of supplementing formal measures with informal information gathering. This could entail the addition of a process approach to assessment, or, more indirect methods such as naturalistic observation, collateral interviews, and an item-level analysis of behavioral-executive-function rating scales.

May 19th, 2013

Here is a reference for Syndromes and Associated Neuroanatomic Localization of Lesions


December 11th, 2012

Blink (2007) observes:

“You see someone, you click, and you’re euphoric.
And in response, your ventral tegmental area uses
chemical messengers such as dopamine, serotonin,
and oxytocin to send signals racing to a part of the
brain called the nucleus accumbens with the good
news, telling it to start craving. [Certain regions]
are deactivated—areas as within the amygdala,
associated with fear (p. 3; cited in Hatfield &
Rapson 2009)”.

April 29th, 2012

Most humans have a clearly dominant hand (usually the right one). What is the lowest form of life that shows such a preference or dominance? Why are most people right-handed?

Birds, which have neuronal populations in the left hemisphere that regulate their song production, are the lowest phylum with a convincing laterality or dominance. The reason for dominance—-its evolutionary or survival advantage—-is unknown.

There are many theories to account for the existence of dominance, but none of them really makes much sense.

March 1st, 2012

2012 AGS Updated Beers Criteria was published in the Journal of the American Geriatrics Society today. Here is the link to that.

The Beers Criteria for Potentially Inappropriate Medication (PIM) Use in Older Adults is one of the most frequently consulted sources of information about the safe prescribing of medications for older adults and is used widely in geriatrics clinical care, training, and research.

For a neuropsychologist, it’s a good idea to check medication interactions and to become aware of potential cognitive side-effects of medication. Multiple drug usage is common in all developed countries. In the U.S., polypharmacy is found in 40% of those older than 65 years. An example of the importance of multiple medications can be seen with drugs that have anticholinergic effects; when more than one drug is taken that has this effect, side effects can include an increase in the patients’ total anticholinergic burden as evidenced by clinical signs such as dry mouth, sedation, confusion and even hallucinations and delirium

February 2nd, 2012

The human eye has 125 million rods, each one containing 1000 folds in its photoreceptor
membrane, with each fold containing 1 million molecules of photoceptor. This extraordinary
light-sensing array can detect one single photon, which is 10 to the (-11 power) watts
(which is 0.00000000001 watts Wow!).

December 7th, 2011

Today in brain cutting didactic we saw a patient who had a massive infarct. It got me thinking about why a stroke is called a stroke.

According to the Oxford English Dictionary, a sudden, inexplicable cerebrovascular accident was first likened to a “stroke of God’s hand” in 1599. The relationship of a cerebral infarction to an act of God exists in other cultures as well: the Greek verb plesso means to “stroke, hit, or beat,” and the derivative plegia gives us our term hemiplegia.
Dirckx JH: Stroke. Stroke 17:559, 1986.

November 16th, 2011

The first description of a neurologic disease appears in the Smith papyrus, which is the oldest known medical text. This ancient papyrus, translated by Edward Smith, consists of a number of “case reports” of different diseases, presented and discussed by an unknown Egyptian author, written about 3300 BC. One of the cases is a person with a traumatic head injury, which is the earliest known description of a neurologic problem.

November 16th, 2011

Doing some reading and I came across a list of people who probably had AD:

1. Ronald Reagan—U.S. president
2. Charlton Heston—actor
3. Rita Hayworth—actress
4. Immanuel Kant—philosopher
5. Ralph Waldo Emerson—writer
6. Maurice Ravel—composer
7. John James Audubon—painter

March 12th, 2011

It is usually considered that the sense of smell is poorly developed in humans, in comparison, for example, to lower vertebrates, such as rats and mice. However, in view of its evolutionary significance, it seems very unlikely that the sense of smell is trivial in guiding human behavior.

The fragility of the fibers in the olfactory mucosa of the nose, their delicate passage through the cribriform plate, and the course of the olfactory tract along the orbital surface of the brain underly the vulnerability of this sensory modality to external trauma—for example, from head injury. This is compounded by the locations of structures receiving the central representations of smell, such as, for example, the primary olfactory cortex and olfactory tubercle, which lie vulnerable on the undersurface of the brain overlying the anterior perforated space.

Smell sensations may occur as part of an aura in temporal lobe epilepsy. Traditionally referred to as uncinate seizures (simple partial seizures in today’s terminology), the seizure focus was thought to be in the uncus, overlying the amygdala. However, olfactory inputs also end in the anterior insula, which thus may be associated with the experience. These aurae therefore have some localizing value, but they are not of lateralizing significance.

The olfactory system is involved in several neuropsychiatric disorders. In depression, for example, the sense of smell can be diminished, as may be other sensory modalities, such as taste or touch. Diminished smell sensation also has been reported in Alzheimer’s disease and Parkinson’s disease, especially the Lewy body variant but not sufficiently reliably to be used in any diagnostic way (Hawkes, 2003). Diminished smell also may be observed early in the course of schizophrenia and may be associated with smaller perirhinal cortices as measured with MRI (Turetsky et al., 2003). Thus, disturbances of smell in such disorders may be associated with underlying neuroanatomical deficits, rather than being simply a manifestation of a psychosis or deteriorating intellect.

November 13th, 2010

Stories of interest for November 12th

August 31st, 2010

Stories of interest for August 30th

August 14th, 2010

Really nice newsletter in pdf format from the Harvard Mahoney Neuroscience Institute; site has back issues from 1992.

August 9th, 2010

Yes, it’s late and I’ve crested 100 pages of writing now; so, I’m a bit loopy.

Here is my joke (wonder who would ever get this):

“Your mommas so dumb, she tried to copyright The Oral Trail Making Test (OTMT)

( © Dinishak 2010)

lol :X

August 6th, 2010

I was up doing literature reviews (ugh) and came across this article by Joseph B. Martin. It is fascinating to me and resonates with me because Dr. Martin is advocating “cross pollination” of neuroscience, neurology, psychology, and medicine; basically, he wants us all to recover from the split that happened at the turn of the century (20th). In some ways the easiest way to explain the split would be to say that science split with philosophy–neurology and neuroscience developed into hard science and medicine while psychology and in some ways psychiatry took the philosophical route. I’m a big advocate of a unified field with sub specialties; psychologists would learn neuroscience and neurologists would learn therapy.

what the field should be

August 6th, 2010

Stories of interest for August 5th

  • Microemboli Study – This is one of the research projects I'm involved in; I'm continuing work with this lab at Stanford and the Veteran's Administration, Palo Alto, to further explore the effects of micrembolization on cognition. There is great debate regarding the neurocognitive effects of CEA and CAS procedures. (It's funny when something you worked on is published and then you don't realize it for a year).