A little History: Phrenology

In this post I will provide a classic in the history of psychology, called phrenology. In phrenology it is tried to provide a localization of function in the brain. The theory was but incorrect. But the story is nostalgic.

Franz Josef Gall (1758-1828) was the originator of the then ninetheenth-century highly popular phrenology. Gall thought that special psychological "faculties" could be assigned to special parts of the brain. Furthermore, Gall thought that the bumps und hills of the skull were related to the brain areas that were underlying it, and were according to him thus associated with these special "faculties" (Fancher, 1996, p. 76). 

By using craniometry, which was supposed te assess the physical parts of the skull, Gall wanted to find support for the shape of the brain underlying the skull (Fancher, 1996, p. 77-78). For instance, an area just above the ear was supposed to be the organ of the faculty "destructiveness".

Stroop Task

The Stroop Task is a classic example in neuropsychology. Participants are presented with words of collor names that are written on a card or screen and have to read and give a response of the wordcolor that is written, irrespective of the the collor name in which the word is written. participants find this task difficult, because they have to overcome a prepotent response to say the color name that is written, instead of the collor the word has. So, for instance, when the word yellow is written in blue people are prone to respond with the answer yellow instead of blue.

Working Memory Deficits in Schizophrenia

Patients with schizophrenia have besides their core symptoms also deficits in the cognitive domain. Patients with schizophrenia are impaired on working memory tasks.

In this post I will start with a discussion of this.

In their review, Park and Goodale (2014) discussed that impairments in working memory, especially concerning encoding and maintenance, are found in a lot of patients with schizophrenia. Furthermore, they stated that the working memory impairments could be a stable trait marker in this patient population, which was to be found to be allready evident in the prodromal phase in addition to the chronic stages of this disorder. In addition, they reported support for the hypothesis that these impairments are genetically transmitted, because these impairments were also found in unaffected relatives.

Cells in the human Brain

There are two types of cells in the brain, neurons and glia. There are three different sorts of neurons: sensory, interneurons, and motor neurons. Through synapses among them they can either exite or inhibit eachother. in addition to neurons, there are a second kind of cells consisting of five types of glial cells. These are called astrocytes, microglia, oligodendroglia and finally schwann cells. The function of glial cells is a supportive one.

Binocural Rivalry

When probing incompatibleimages to the eyes results in conscious perception appears. This phenomenon is called binocural rivalry (Alais and Melcher, 2006). the complexity of a cue is a significant effect in the process of rivalry while it makes the depth and a rivalry process that showed cohesion (Alais and Melcher, 2006). when complexity of real world images are paired with gratings with a deep attenuation coherence is also complex. When non complex images are used there is an effect of lower processing.When both eyes receive images that are globel it results in a highly coherent state.

He and Davis (2001) suggest that inserted information in the blind spot has a contribution to the process of binocular rivalry.

Alpers and Gerdes (2007) investigated binocular rivalry in order to assess if emotionally important pictures show an advantage over neutral pictures when the were visually proccessed. Visual perception was improved by preferential processing due to binocular rivalry. In addition it is suggested that emotional pictures are not only the cause of different characteristics of these pictures.

Hancock and Andrews (2007) wanted to see if and how attention is related in the selection and perpetuation of perceptual dominance occuring during binocular rivalry. Participants had to fixate on a dark spot that was centrally in view during viewing a plaid stimulus that was given to the two eyes. In one occasion the plaid rotated either clockwise or counterclockwise whereafter it returned to the original locus. During a dalay, the grating that was presented was removed from the image in one eye and the grating that was uncued to the other eye, resulting in binocular rivalry. It was found that involuntary cuing resulted in the fact that the stimulus was easier perceived.

Response Inhibition in ADHD as revealed by event-related potentials (ERP's)

Here I post some interesting findings on behavioral inhibition in attention deficit hyperactivity disorder as revealed by event-related potentials (ERP's). ERPs are measured on the scalp while the participant is performing a task. Repeated presentation of stimuli results in a brainwave component that is associated with the particular task. In patients with ADHD, respons inhibition is one of the most impaired in its cognition (Liotti, Pliszka, Perez, Luus, Glahn, and Semrud-Clikeman, 2007). The core symptoms of ADHD are attentional impairments, hyperactivity, impulsivity as well as problems in the inhibition of responses (American Psychiatric Association, 1994). The neural generators of response inhibition can be investigated with a high amount of temporal resulation by recording ERP's from the subject's scalp. In the experiment of Liotti et al. (2007) children with ADHD performed on the Stop Signal Task (SST). Briefly, the participants had to make a discrimination among the letters 'A' and 'B', Which were the 'go' stimuli In which they had to respond either with their left or right index finger. Go stimuli were presented with different delays in time Which were equally possible. When an 'S' appeared on screen, this was the stop signal and occured in twenty-five percent of the cases. When subjects saw an 'S' they had to inhibit their response. Electrophysiologically, several brain wave were found to be abnormal in children with ADHD Compared to the healthy children control group. The Stop Signal N200 wave was found to be largly reduced in ADHD children. The source of this ERP component was to be found reduced in right inferior frontal parts of the brain (Liotti et al., 2007). The NoGo (Stop) attenuation is suggested be due to early inhibitory impairments in ADHD. In addition to a reduced N200 ERP component, also the Stop Signal NoGo P3 was found to be reduced.

Neuroeconomics

In this post I give a brief overview of the recent field of neuroeconomics. It includes insights from economics, psychology, and neuroscience. Neuroeconomics is a very new discipline with an interaction of economics, psychology, and neuroscience (Reuter and Montag, 2016). The aim of neuroeconomics is studying decision making in human beings with a focus on its brain mechanisms. Neuroeconomics can be investigated with functional magnetic resonance imaging (fMRI), however, other techniques are also of interested use, such as EEG, genetics, endocrinology, and transcranial magnetic stimulation (TMS). Game Theory plays a mathematical role in neuroeconomics, which have grown out of economic game theory and behavioral economics. The aspects of game theory can be used to invent ideas of neuroscience about the brain, as well as psychological aspects concerning the mind and predictions of economic human behavior (Reuter and Montag, 2016).

Game theory is the study of mathematically objects which states and purposes do interact with each  other. From a neuroscience standpoint, game theory might be applied to assess the competitive firing of populations of neurons (Reuter and Montag, 2016).

The aim of neuroeconomics is to link neurophysiological and behavioral aspects of the decision process accordingly, and afterwards associate these links to psychological and mental activity aspects by making use of the formal models concerning game theory for the prediction, specification, and comparison of neural activity in the brain that is associated with decision making (Reuter and Montag, 2016).

The economic game has three basic objects. Firstly, there are the players. These are independent decision makers. Secondly, there are actions, which are described from the actions of a single player that makes it while performing the game. These actions might be divided among separate points of time, the situationally associated circumstances or at the stage in which the game is into. Finally, the third object, are the overall outcomes and as its consequences its utility that each one player has experienced (Reuter and Montag, 2016).