Introduction
Autism spectrum disorder (ASD) is a condition that affects how people interact with others and perceive the world. People with ASD often have difficulties in social communication, attention, memory, and executive functions. These cognitive skills are essential for learning, problem-solving, and adapting to different situations.
But what causes these difficulties in ASD? And how can we help people with ASD improve their cognitive abilities?
One possible answer lies in the brain waves, or oscillations, that reflect the activity of large groups of neurons. Brain waves are measured by electroencephalography (EEG), a technique that records the electrical signals from the scalp. Different types of brain waves are associated with different cognitive processes, such as perception, attention, memory, and emotion.
Researchers have found that people with ASD have abnormal patterns of brain waves compared to typically developing people. For example, they may have less synchronization (or coherence) between different brain regions, or more variability (or entropy) in their brain wave frequencies. These alterations may impair the communication and integration of information within and between brain networks, leading to cognitive deficits.
In this blog post, we will review the evidence of how brain waves affect cognitive performance in children and adolescents with ASD. We will focus on five key cognitive domains: social cognition, attention, working memory, inhibitory control, and cognitive flexibility. We will also discuss the potential implications of these findings for developing new therapies based on non-invasive brain stimulation techniques.
Social Cognition
Social cognition is the ability to understand and respond to the mental states, emotions, and intentions of others. It is crucial for social interaction and empathy. People with ASD often have impairments in social cognition, such as recognizing facial expressions, understanding sarcasm, and inferring others’ beliefs and desires.
Several studies have shown that social cognition is related to brain waves in the alpha (8-12 Hz) and gamma (30-80 Hz) bands. Alpha waves are involved in filtering out irrelevant information and focusing on relevant stimuli. Gamma waves are involved in binding together different features of a stimulus and creating a coherent perception.
People with ASD tend to have lower alpha coherence and higher alpha entropy than typically developing people, especially in the right hemisphere and the frontal regions. This suggests that they have difficulties in suppressing distractors and attending to social cues. They also tend to have lower gamma coherence and higher gamma entropy than typically developing people, especially in the left hemisphere and the temporal regions. This suggests that they have difficulties in integrating different aspects of social stimuli and forming a holistic representation.
These alterations in brain waves may explain why people with ASD have problems in social cognition, such as recognizing emotions, understanding jokes, and inferring mental states.
Attention
Attention is the ability to select and maintain focus on relevant information while ignoring irrelevant information. It is essential for learning, memory, and executive functions. People with ASD often have difficulties in attention, such as shifting attention, sustaining attention, and dividing attention.
Several studies have shown that attention is related to brain waves in the theta (4-8 Hz) and alpha bands. Theta waves are involved in alertness, arousal, and memory encoding. Alpha waves are involved in filtering out irrelevant information and focusing on relevant stimuli.
People with ASD tend to have lower theta coherence and higher theta entropy than typically developing people, especially in the frontal and central regions. This suggests that they have difficulties in maintaining a high level of alertness and encoding new information. They also tend to have lower alpha coherence and higher alpha entropy than typically developing people, especially in the parietal and occipital regions. This suggests that they have difficulties in suppressing distractors and attending to relevant stimuli.
These alterations in brain waves may explain why people with ASD have problems in attention, such as shifting attention, sustaining attention, and dividing attention.
Working Memory
Working memory is the ability to temporarily store and manipulate information in the mind. It is important for reasoning, problem-solving, and planning. People with ASD often have difficulties in working memory, such as updating, monitoring, and manipulating information.
Several studies have shown that working memory is related to brain waves in the theta and alpha bands. Theta waves are involved in memory encoding and retrieval. Alpha waves are involved in filtering out irrelevant information and focusing on relevant stimuli.
People with ASD tend to have lower theta coherence and higher theta entropy than typically developing people, especially in the frontal and central regions. This suggests that they have difficulties in encoding and retrieving information in working memory. They also tend to have lower alpha coherence and higher alpha entropy than typically developing people, especially in the parietal and occipital regions. This suggests that they have difficulties in suppressing distractors and attending to relevant stimuli in working memory.
These alterations in brain waves may explain why people with ASD have problems in working memory, such as updating, monitoring, and manipulating information.
Inhibitory Control
Inhibitory control is the ability to suppress inappropriate or impulsive responses and act according to the rules or goals. It is necessary for self-regulation, impulse control, and behavioral flexibility. People with ASD often have difficulties in inhibitory control, such as inhibiting prepotent responses, switching tasks, and stopping ongoing actions.
Several studies have shown that inhibitory control is related to brain waves in the theta and beta (13-30 Hz) bands. Theta waves are involved in alertness, arousal, and memory encoding. Beta waves are involved in motor control, action selection, and feedback processing.
People with ASD tend to have lower theta coherence and higher theta entropy than typically developing people, especially in the frontal and central regions. This suggests that they have difficulties in maintaining a high level of alertness and encoding new information in inhibitory control. They also tend to have lower beta coherence and higher beta entropy than typically developing people, especially in the frontal and central regions. This suggests that they have difficulties in controlling their motor responses, selecting appropriate actions, and processing feedback in inhibitory control.
These alterations in brain waves may explain why people with ASD have problems in inhibitory control, such as inhibiting prepotent responses, switching tasks, and stopping ongoing actions.
Cognitive Flexibility
Cognitive flexibility is the ability to adapt to changing situations, rules, or goals. It is essential for creativity, innovation, and learning from experience. People with ASD often have difficulties in cognitive flexibility, such as generating novel ideas, finding alternative solutions, and learning from errors.
Several studies have shown that cognitive flexibility is related to brain waves in the theta and gamma bands. Theta waves are involved in memory encoding and retrieval. Gamma waves are involved in binding together different features of a stimulus and creating a coherent perception.
People with ASD tend to have lower theta coherence and higher theta entropy than typically developing people, especially in the frontal and central regions. This suggests that they have difficulties in encoding and retrieving information in cognitive flexibility. They also tend to have lower gamma coherence and higher gamma entropy than typically developing people, especially in the frontal and temporal regions. This suggests that they have difficulties in integrating different aspects of stimuli and forming a holistic representation in cognitive flexibility.
These alterations in brain waves may explain why people with ASD have problems in cognitive flexibility, such as generating novel ideas, finding alternative solutions, and learning from errors.
Implications and Future Directions
The evidence reviewed in this blog post suggests that people with ASD have abnormal patterns of brain waves that affect their cognitive performance in various domains. These findings may have important implications for developing new therapies based on non-invasive brain stimulation techniques, such as transcranial magnetic stimulation (TMS) and transcranial direct current stimulation (tDCS).
These techniques can modulate the activity of specific brain regions and networks by applying magnetic or electric fields to the scalp. They can potentially enhance or normalize the brain waves associated with cognitive functions in ASD, such as alpha and gamma coherence, and theta and beta entropy. By doing so, they may improve the cognitive abilities and quality of life of people with ASD.
However, more research is needed to determine the optimal parameters, protocols, and outcomes of these techniques for ASD. Moreover, individual differences in brain anatomy, physiology, and genetics should be taken into account to tailor the stimulation to each person’s needs and preferences. Finally, the long-term effects and safety of these techniques should be carefully evaluated before they are widely implemented in clinical practice.
Faq
What are the main types of brain waves?
The main types of brain waves are delta (0.5-4 Hz), theta (4-8 Hz), alpha (8-12 Hz), beta (13-30 Hz), and gamma (30-80 Hz). Delta waves are associated with deep sleep and unconsciousness. Theta waves are associated with alertness, arousal, and memory encoding. Alpha waves are associated with filtering out irrelevant information and focusing on relevant stimuli. Beta waves are associated with motor control, action selection, and feedback processing. Gamma waves are associated with binding together different features of a stimulus and creating a coherent perception.
What is the difference between coherence and entropy in brain waves?
Coherence and entropy are two measures of brain waves that reflect the synchronization and variability of the neural activity, respectively. Coherence is the degree of similarity or correlation between the brain waves of different brain regions or electrodes. It indicates how well the brain regions or networks communicate and coordinate with each other. Entropy is the degree of randomness or unpredictability of the brain wave frequencies. It indicates how complex and flexible the brain dynamics are.
What are the main differences and similarities between the ASD and the typically developing groups in the brain waves and the cognitive performance?
The main differences and similarities between the ASD and the typically developing groups in the brain waves and the cognitive performance are:
- Differences: The ASD group has lower coherence and higher entropy in the brain waves than the typically developing group, especially in the alpha and gamma bands, across all the cognitive domains. This means that the ASD group has less synchronization and more variability in the neural activity than the typically developing group. The ASD group also has lower cognitive performance than the typically developing group, especially in the domains of social cognition, attention, working memory, inhibitory control, and cognitive flexibility. This means that the ASD group has more difficulties in understanding and interacting with other people, selecting and focusing on the relevant information, storing and manipulating information for a short period of time, suppressing or overriding unwanted or inappropriate responses or impulses, and switching or adapting to different rules, demands, or perspectives.
- Similarities: The ASD group and the typically developing group have similar coherence and entropy in the brain waves in some of the bands and domains, such as the theta and beta bands, and the working memory and cognitive flexibility domains. This means that the ASD group and the typically developing group have similar levels of synchronization and variability in the neural activity in some of the bands and domains. The ASD group and the typically developing group also have similar cognitive performance in some of the domains, such as the working memory and cognitive flexibility domains. This means that the ASD group and the typically developing group have similar abilities in storing and manipulating information for a short period of time, and switching or adapting to different rules, demands, or perspectives.
How do TMS and tDCS work?
TMS and tDCS are non-invasive brain stimulation techniques that can modulate the activity of specific brain regions and networks by applying magnetic or electric fields to the scalp. TMS uses a coil that generates a magnetic field that induces an electric current in the underlying brain tissue. TMS can stimulate or inhibit the neural activity depending on the frequency, intensity, and duration of the magnetic pulses. tDCS uses a pair of electrodes that deliver a low-intensity direct current to the brain. tDCS can increase or decrease the neural excitability depending on the polarity, intensity, and duration of the electric current.
What are the benefits and risks of using TMS and tDCS for ASD?
TMS and tDCS may have some benefits and risks for ASD, such as:
- Benefits: TMS and tDCS may improve the cognitive performance and quality of life of people with ASD by enhancing or normalizing the brain waves associated with cognitive functions, such as alpha and gamma coherence, and theta and beta entropy. TMS and tDCS may also have positive effects on other aspects of ASD, such as mood, sleep, or sensory processing.
- Risks: TMS and tDCS may have some adverse effects or complications, such as seizures, headaches, or skin irritation. TMS and tDCS may also have unpredictable or variable effects, depending on the individual’s brain anatomy, physiology, and genetics. TMS and tDCS may also have ethical or social implications, such as the potential for misuse, abuse, or coercion.
How can I improve or normalize my or my family member’s brain waves without using TMS or tDCS?
If you want to improve or normalize your or your family member’s brain waves without using TMS or tDCS, you can:
- Engage in regular physical exercise, such as walking, running, or swimming, which can increase the blood flow and oxygen to the brain and enhance the brain waves.
- Practice mindfulness meditation, such as breathing, body scan, or loving-kindness, which can reduce the stress and anxiety and increase the alpha and gamma waves.
- Listen to music, such as classical, ambient, or binaural beats, which can stimulate the mood and emotion and modulate the theta and beta waves.
- Play games, such as puzzles, chess, or sudoku, which can challenge the cognitive skills and boost the theta and alpha waves.
- Learn new skills, such as languages, instruments, or arts, which can enrich the brain plasticity and diversity and increase the gamma and beta waves.
What are some of the theoretical and conceptual contributions and implications of the research paper for the research and practice of ASD?
Some of the theoretical and conceptual contributions and implications of the research paper for the research and practice of ASD are:
- The research paper provides a comprehensive and updated framework and model of how brain waves affect cognitive performance in ASD, by integrating and synthesizing the evidence from multiple studies, domains, and bands, as well as by performing a meta-analysis of the data.
- The research paper supports and extends the existing theories and hypotheses of ASD, such as the underconnectivity theory, the neural noise theory, the predictive coding theory, and the excitation-inhibition imbalance theory, by providing empirical and quantitative support and validation for them.
- The research paper challenges and questions the existing assumptions and paradigms of ASD, such as the homogeneity and stability of ASD, the specificity and universality of ASD, and the deficit and pathology of ASD, by highlighting the diversity and variability of ASD, the context and task dependency of ASD, and the compensation and adaptation of ASD.
- The research paper proposes and suggests new directions and perspectives for the research and practice of ASD, such as the personalized and evidence-based approaches, the interdisciplinary and transdisciplinary perspectives, and the collaborative and participatory methods.
Source: