diff --git a/reasoning_gym/cognition/arc_1d.py b/reasoning_gym/cognition/arc_1d.py
new file mode 100644
index 00000000..ed183df8
--- /dev/null
+++ b/reasoning_gym/cognition/arc_1d.py
@@ -0,0 +1,55 @@
+from random import Random
+from typing import Optional, Dict, List
+
+
+def gen_field(size: int, color: int = 0) -> List[int]:
+    """Generate a field of given size filled with specified color (default 0)."""
+    return [color] * size
+
+
+def write_block(pos: int, block: List[int], field: List[int]) -> List[int]:
+    """Write a block into a field at given position."""
+    result = field.copy()
+    for i, color in enumerate(block):
+        result[pos + i] = color
+    return result
+
+
+def task_move_n_pix(size: int, move_pix: int, solid: bool, rng: Random) -> Optional[Dict[str, List[int]]]:
+    """
+    Generate a task where a block is moved to the right by move_pix pixels.
+
+    Args:
+        size: Size of the field
+        move_pix: Number of pixels to move the block
+        solid: If True, block is single color; if False, block has random colors
+        rng: Random number generator
+
+    Returns:
+        Dictionary with 'input' and 'output' fields containing the puzzle,
+        or None if valid puzzle cannot be generated
+    """
+    # Validate size constraints
+    if size <= move_pix + 1:
+        return None
+
+    # Generate block size and position
+    block_size = rng.randint(1, size - move_pix - 1)
+    block_pos = rng.randint(0, size - block_size - move_pix)
+
+    # Generate the block
+    if solid:
+        # For solid blocks, use single random color (1-9)
+        color = rng.randint(1, 9)
+        block = [color] * block_size
+    else:
+        # For non-solid blocks, each position gets random color (1-9)
+        block = [rng.randint(1, 9) for _ in range(block_size)]
+
+    # Create input field with block at initial position
+    question = write_block(block_pos, block, gen_field(size))
+
+    # Create output field with block moved right by move_pix
+    answer = write_block(block_pos + move_pix, block, gen_field(size))
+
+    return {"input": question, "output": answer}