Download Michael Palladino Natalie Pebbles Spenser Mitchell Summary of

Michael Palladino
Natalie Pebbles
Spenser Mitchell
Summary of:
Ketteler, D., & Ketteler, S. (2010). Is schizophrenia “the price that Homo sapiens pays
for language”? Sub cortical language processing as the missing link between
evolution and language disorder in psychosis—A neurolinguistic approach.
Journal of Neurolinguistics, 23(4), 342-353. doi:10.1016/j.jneuroling.2010.04.003
Ketteler and Ketteler(2010) emphasize the importance of language impairment as
one of the core symptoms of Schizophrenia. Research has postulated that, according to
the ICD-10 diagnostic criteria for Schizophrenia, “language symptoms like
semantic/phonemic paraphasias or poverty of speech were superior to nuclear
symptoms[e.g. delusions](343). It has been proposed that the delusions are in fact a
manifestation of language impairment (343).
Ketteler and Ketteler propose that there are two approaches to understanding the
neurological basis of schizophrenia . First, they propose that hemispheric imbalances aid
in the development of schizophrenia (350). This notion is supported by research in the
article that showed that, “decreased lateralization was significantly correlated to the
severity of hallucinations.”(344). Hallucinations and delusions, characteristic symptoms
of Schizophrenia, may be caused by a breakdown in lateralsation. Thoughts what is
perceived as coming from within by a normally functioning brain may be perceived as
coming from an external source. Similarly, auditory hallucinations can be perceived as
coming from another person as a running commentary on the action being performed by
the Schizophrenic patient (344). Recent studies have found that persons at high risk for
Schizophrenia, i.e. children of a Schizophrenic patient, an identical or fraternal twin of a
Schizophrenic, have structural abnormalities that exist in regions of the brain associated
with language processing (345). Furthermore, research supports the importance of the
Foxp2 gene’s role in patients suffering from Schizophrenia characterized by auditory
hallucinations. A case study of a third generation Schizophrenia sufferer highlights the
role of the Foxp2 gene in producing language disorder (specifically verbal dyspraxia) and
its link to auditory hallucinations. It has been proposed that, “auditory hallucinations
represent a disorder of speech rather than a unique group of psychotic symptoms.”(346).
Evolutionarily, the hemispheric segregation of the brain aided in our ability to stand upright (345-6), therefore this research would support the notion that Schizophrenia is the
price we pay.
The second approach to understanding Schizophrenia posed by the authors is the
role specific brain structures play in higher order language functioning. The article
suggests that these language impairments may be genetically inherent in patients with
Schizophrenia. Evidence of this can be seen in the negative reaction that is elicited when
Schizophrenic patients are asked to interpret ambiguous terms. This has been
hypothesized as a, “pathogonomical marker for psychotic language processing… and for
the lack of a Theory of Mind”(347) in patients suffering from Schizophrenia. The
suggested variable of difficulty interpreting ambiguous stimuli has been tested using
Lexical Decision Tasks(LDT). Patients with Schizophrenia have shown consistent
impairment in their ability to select the appropriate context from an ambiguous stimuli
(347). In an experiment comparing the results of an LDT between Schizophrenic patients
and controls, it was found that, “the right hemisphere exhaustively activates the various
meanings with a word, while the left hemisphere’s initial access is selectively restricted
to the dominant meaning.”(348). This supports the hypothesis that hemispheric
interaction problems are a major contributor to Schizophrenia.
Another important brain region that is postulated to be effected by
Schizophrenia is the caudate nuclei, a region of the Basal Ganglia involved in learning
and memory amongst other things. It has been found that stimulation of this brain area
brings about irrelevant language, a major symptom of Schizophrenia. This result has been
found in the extended use of antipsychotic drugs. The prolonged use of these drugs has
been associated with increases in caudate volume. Another brain region that has been
found to be associated with Schizophrenia are the Thalamas. There is strong evidence
that suggests that, “ basal ganglia and thalamus changes in schizophrenic patients cause
cortical dysfunction in several language related cortical areas (e.g. superior frontal
gyrus)”(350).
Though much future research needs to be done on the importance of
language impairment as a distinctive or casual feature of Schizophrenia it is an new and
exciting approach to a disorder that has gone misunderstood for many years.
Test Questions
1. Which is NOT an approach to understanding the neurological basis of
schizophrenia that is proposed by Ketteler and Ketteler?
a. Hemispheric Imbalances
b. Overactive Limbic System
c. Specific roles of brain structures in higher order language functioning and
their effect on the disorder
2. The article suggests that major symptoms of schizophrenia such as delusions may
be a manifestation of language impairment.
a. True
b. False
3. Evolutionary, the hemispheric segregation of the brain (lateralization) aided in our
ability to:
a. Think Creatively
b. Stand Upright
c. Memorize Information
d. Make Tools
4. Research has shown that decreased lateralization significantly correlates with
a. Severity of hallucinations
b. Ability to speak
c. Reading comprehension
d. Ability to hear
5. The article suggests that the negative reactions elicited in patients with
schizophrenia when asked to interpret ambiguous terms is evidence that that
certain language impairments may be genetically inherent in patients with
schizophrenia
a. True
b. False
6. In the article, it is suggested that young children who grow up with speech
impediments have an increased risk of schizophrenia
a. True
b. False
Answer Key
1.
2.
3.
4.
5.
6.
B
A
B
A
A
B