L1 - Introduction

Lecture + Textbook Chapter(s) 2 & 4

Neuropsychology

A branch of psychology that studies the relationship between the brain’s physical structures and processes, and human behavior, emotions, and cognition.

Working Domains of Neuropsychologists

• Hospitals (Most Common)

• Mental health care (GGZ) (Most Common)

• Rehabilitation centres

• Forensic institutions

• Residential or nursing homes

• Specialized institutions (e.g., centers for epilepsy or visual impairments)

• Other

Subtraction Method

Use of mental chronometry. Basically, they measure the reaction time to a response. Then they measure the reaction time to a response with something like discrimination and/or selection. They then subtract the normal reaction time to a response from the discrimination and/or selection to measure the cognitive process speed of discrimination and/or selection.

Mental Chronometry

The scientific study of reaction time (RT) to infer the speed, duration, and nature of cognitive processes, including perception, memory, and decision-making. Involves the reaction time paradigm and pure insertions.

Reaction Time Paradigm

The use of reaction times to evaluate cognitive processes.

Pure insertions

A single cognitive process can be inserted into a task without affecting the duration of other processes.

Subtraction Method Criticisms (2!)

1. Fallacies of pure insertion: attention, memory, etc. (Solution → Include multiple tasks).

2. Limited ecological validity: gap between everyday life and in a lab (Solution → VR/AR, Add Questionnaires + Observations)

Single Dissociation

Double Dissociation

Demonstrates that two (more or less) independent cognitive processes rely on different brain regions or mechanisms (= parallel organization).

However: Even a single, unified neural network can sometimes behave like it has separate systems. So, if two patients show a double dissociation that doesn't automatically mean their brains have two separate, independent modules. A single system can still produce that pattern.

Normal Range of Performance is What?

It falls between - and + 2 Standard Deviation (SD)

Interpretation of Dissociation

1. Scores on one task should significantly fall above or below the average of the normative group (more than -/+ 2SD).

2. The differences between the performances on task A and B differ significantly from each other.

2 Types of Imaging Techniques

1. Structural (CT, MRI → DTI, VBM, MRS)

2. Functional (fMRI, PET, EEG, ERP, MEG)

2 Types of Resolutions

1. Temporal Resolution → Speed of the recording.

2. Spatial Resolution → Sharpness of the image.

Computerized Tomography (CT)

Advantages:

• High Spatial Resolution

• Produces slices of the brain (X-Ray Images).

• Cheap and quick.

• Low Temporal Resolution.

Disadvantages:

• Subtle Abnormalities are.

• Harmful to children and unborn babies.

Workings:

• Damages processes in the brain produce more water, making the image darker in those areas. Blood and calcium are white in the image.

Radiological Contrast Agent

It is a substance introduced into the body to enhance the visibility of internal structures, tissues, or fluids during imaging tests.

Magnetic Resonance Imaging (MRI)

Advantages:

• High Spatial Resolution

• MRI distinguishes between gray and white matter (CT does not).

Disadvantages:

• High Cost

• Time Consuming

• Claustrophobia

Workings:

• Basically, water molecules are in the brain: the magnet aligns the water molecules then disrupts them and measures the energy released when they realign to create the image.

Functional Magnetic Resonance Imaging (fMRI)

Advantages & Disadvantages of fMRI are basically the same as MRIs..

Workings:

• Super large magnet goes around you and measures Blood-Oxygenated Level Dependent (BOLD) → measures ratio between blood-poor and blood-rich hemoglobin.

• Increased activity in brain areas = higher levels of blood!

Electroencephalography (EEG)

Advantages:

• Very safe!

• High temporal resolution.

• Cheap & quick!

Disadvantages:

• Only measures top level activity, not deeper.

Workings

• Measures electrical activity produced by the brain cells.

Positron Emission Tomography (PET)

Advantages:

• Good for medicine.

Disadvantages:

• High cost

• Radiation

Workings

• Measures electrical activity produced by the brain cells.

EEG Brain Waves (DTABG)

Delta → Deep Sleep

Theta → Drowsiness, Light Sleep

Alpha → Relaxed, Calm

Beta → Alert, Focused

Gamma → High-Level Attention

Empirical Cycle Steps (OIDTE)

Observation → Induction → Deduction → Testing → Evaluation

Ratio Score

A score which indicates how the more complex condition relates to the simple condition.

Practice Effects

The occurrence of improvement in performance with repetition of tasks.

Types of Research

Observational/Descriptive, Correlational, (Quasi-) Experimental.

Meta-Analysis, Literature & Systematic Review

Literature Review → research question is answered by summarising previous find-

ings.

Systematic Review → Criteria are defined in advance about which studies

will be included in the review and all research articles that meet these criteria

are included.

Meta-Analysis → Data from previous studies are combined and dedicated analysis

software can be used to statistically test whether the various findings correspond

with or contradict each other.

Intention-To-Treat Analysis

Analysing the groups as they were assigned at the start.

Cross-Over Design

• A crossover design is a type of RCT.

• In crossover designs, participants receive not one but several interventions, and the effect of the interventions is compared within participants.

• The AB/BA design is the simplest example of a cross-over design

Multiple-Baseline Design

Multiple-baseline design is taking several baseline measurements to determine what the baseline is and/or how recovery is progressing.

Longitudinal

A cohort study is a longitudinal study in which a specific group of people ( cohort) is followed for a longer period of time, often several years.

Cross-Sectional Design

• Measurements are made at one point in time. This allows, for example, a look at the prevalence of a particular disease.

• It also allows the study of people of different ages or people who are at different times in the disease progression, without any test-retest effects. However, cross-sectional research is correlational….

Case Studies

• In case studies, one person (single-case-study) or several people (case-series) are thoroughly studied.

• The purpose of a case study is not to obtain results that are directly generalisable, but to collect data about unique individuals or groups.

Heterogeneity & Homogeneity

Heterogeneity → When something has a variety.

Sometimes you need a sample that has many varied features in order to generalise - this also depends on the research question.

Sometimes you may want homogeneity → when something is not varied.

Open Science & Errors

• All about transparent and accessible research!

• The aim of open science is to improve the quality of scientific research, for example by evaluating the reproducibility and replicability of findings.

• Open science also involves reporting null findings.

• Preregistration.

• Type 1 Error → False Positive

• Type 2 Error → False Negative

PICO Method

People_, Intervention, Control, Outcome.

Two types of neuropsychological research

1. Fundamental neuropsychological research

2. Clinically oriented neuropsychological research

Fundamental Research

Focuses on understanding the cognitive disorders/processes and related brain structures.

Clinically Oriented Research

Focuses on improving the assessment and treatment of brain disorders.